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Forecast Discussion - NOAA's National Weather Service Latest: AFDPBZ| AFDLWX| AFDPHI| AFDAKQ| [top] 000 FXUS61 KPHI 091516 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1116 AM EDT THU SEP 9 2010 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL REMAIN NEAR NORTHERN NEW ENGLAND TODAY, THEN GRADUALLY SHIFT EASTWARD TONIGHT AND FRIDAY. MEANWHILE, HIGH PRESSURE OVER THE MIDWEST WILL SLOWLY SHIFT EASTWARD THROUGH FRIDAY NIGHT, EVENTUALLY SETTLING OVER OUR AREA SATURDAY. THIS HIGH PRESSURE SYSTEM WILL THEN MOVE OFFSHORE LATE SATURDAY. A COLD FRONT WILL CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT SLIDES THROUGH LATE TUESDAY, THEN HIGH PRESSURE BEGINS TO BUILD TOWARD OUR AREA WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PRESSURE GRADIENT BETWEEN A LOW PRESSURE SYSTEM OVER NORTHERN NEW ENGLAND AND HIGH PRESSURE OVER THE WESTERN GREAT LAKES IS YIELDING NORTHWEST WINDS ACROSS THE REGION OF 15 TO 20 KNOTS WITH GUSTS AROUND 25 KNOTS. EXPECT THESE TYPE OF WINDS THROUGH THE AFTERNOON BEFORE DIMINISHING DURING THE EVENING HOURS. STRATOCU COVER HAS THICKENED AS EXPECTED THROUGH THE NORTHERN ZONES, AND A MENTION OF SPRINKLES WAS MAINTAINED FOR EXTREME NORTHERN NEW JERSEY AND THE POCONOS FOR THIS AFTERNOON. HIGH TEMPS RANGING FROM THE MID 60S NORTH TO MID AND UPPER 70S SOUTH APPEAR TO BE ON TRACK. OUR WEATHER TODAY WILL BE CONTROLLED BY A STRONG CLOSED LOW ANCHORED NEAR NORTHERN NEW ENGLAND WITH CYCLONIC FLOW OCCURRING ACROSS THE MID ATLANTIC AND NORTHEAST. A NORTHWESTERLY FLOW OF COOLER AIR WILL COMBINE WITH A TIGHTENED PRESSURE GRADIENT TO PRODUCE BREEZY TO WINDY CONDITIONS. THE WINDS HAVE DIMINISHED HOWEVER AS DAYTIME HEATING OCCURS, THE BOUNDARY LAYER MIXING WILL DEEPEN WITH TIME ALLOWING FOR BETTER VERTICAL MIXING. IF WE MIX TO THE FULL POTENTIAL, WE WOULD BE ABLE TO TAP SOME 25 KNOTS OF WIND. THEREFORE, WE WILL CONTINUE TO CARRY INCREASED WINDS THROUGH THE DAY, BEFORE SOME DROPPING OFF IS EXPECTED TOWARD SUNSET AS THE LOSS OF DAYTIME HEATING OCCURS. THE CYCLONIC FLOW COUPLED WITH CAA AND ADDED MOISTURE FROM THE GREAT LAKES CONTINUES TO GENERATE A WEALTH OF STRATOCUMULUS TO OUR NORTHWEST. AN AREA OF CHANNELIZED VORTICITY IS LIKELY ENHANCING THIS CLOUD COVER, AND THIS VORTICITY IS FORECAST TO BE MAINTAINED THROUGH TODAY AND EVEN SETTLE SOUTHWARD SOME. THIS WILL TEND TO KEEP CLOUDS MORE CONCENTRATED THE FARTHER NORTH ONE GOES. THE FORECAST CHALLENGE TODAY IS HOW MUCH IN THE WAY OF STRATOCUMULUS CAN EITHER BE PULLED INTO OUR AREA OR FORM. THE FORECAST SOUNDINGS HAVE A HINT OF A LITTLE INSTABILITY DEVELOPING THIS AFTERNOON AS BOUNDARY LAYER MIXING IS MAXIMIZED. THIS SHALLOW RIBBON OF INSTABILITY IS WHERE THE CLOUDS WOULD BE AND THIS POINTS MAINLY ACROSS OUR NORTHERN ZONES. FARTHER SOUTH, THE CHANNELIZED VORTICITY IS FORECAST TO ARRIVE MUCH LATER IN THE DAY AND THE AIR MASS IS ACTUALLY DRIER WITH MORE OF A CAP. THE FLY IN THE OINTMENT WOULD BE IF CLOUDS DEVELOP SINCE THE CONVECTIVE TEMPERATURES SHOULD BE REACHED AND THE MOISTURE BECOMES TRAPPED UNDER THE INVERSION. WE ARE LEANING TOWARD THIS AND FOR NOW WE INCREASED THE SKY COVER SOME BUT STILL MAINTAINED MORE COVERAGE UP NORTH COMPARED TO DOWN SOUTH. THE NORTHWESTERLY FLOW IS GENERATING LAKE EFFECT RAIN SHOWERS ACROSS WESTERN AND CENTRAL NEW YORK. THE TRAJECTORY WOULD FAVOR THIS BEING PUSHED TOWARD NORTHEASTERN PENNSYLVANIA, AND THIS COULD BE HELPED TO SOME EXTENT BY THE CHANNELIZED VORTICITY. SINCE THIS ACTIVITY WOULD BE MOVING FARTHER AWAY FROM ITS MAIN MOISTURE SOURCE /LAKES ONTARIO AND ERIE/, PERHAPS A LIGHT SHOWER OR SOME SPRINKLES GET TO THE SOUTHERN POCONOS AND FAR NORTHWESTERN NEW JERSEY. AM NOT REAL CONFIDENT IF MEASURABLE PRECIPITATION OCCURS, THEREFORE WILL GO WITH POPS BELOW 15 PERCENT AND ADD A CHC OF SPRINKLES FOR NOW. AS FOR TEMPERATURES, WE GENERALLY SIDED WITH A BLEND OF THE GFS/NAM MOS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE LARGE CLOSED LOW OVER NEW ENGLAND IS FORECAST TO SLIDE SOUTHWARD TONIGHT, PUSHING THE CHANNELIZED VORTICITY THROUGH THE NORTHERN MID ATLANTIC REGION. THE GFS ACTUALLY HAS A MORE FOCUSED SHORT WAVE ROTATING AROUND THE CLOSED LOW, WHILE SOME OF THE OTHER GUIDANCE IS MORE CHANNELIZED. WE ARE NOT ANTICIPATING ANY PRECIPITATION WITH THIS, HOWEVER IT MAY IMPACT THE CLOUD COVER FORECAST. THERE SHOULD BE A FAIR AMOUNT OF STRATOCUMULUS AROUND IN THE EVENING WITH MORE UP NORTH COMPARED TO THE DELMARVA. WITH THE LOSS OF DAYTIME HEATING, THE STRATOCUMULUS SHOULD TEND TO FLATTEN OUT AND DISSIPATE FROM SOUTH TO NORTH. THE NORTHERN ZONES SHOULD TEND TO HOLD ONTO MORE IN THE WAY CLOUDS LONGER GIVEN THE CLOSER PROXIMITY OF THE CLOSED LOW AND THE NORTHWESTERLY FLOW OFF THE EASTERN GREAT LAKES. WHILE THE PRESSURE GRADIENT IS FORECAST TO REMAIN TIGHTENED TONIGHT ALONG WITH SOME CAA, WE SHOULD BE ABLE TO DECOUPLE MORE QUICKLY AS THE LOW-LEVEL FLOW IS WEAKER AND THE BOUNDARY LAYER BECOMES MORE SHALLOW AND COOLS. FOR FRIDAY, THE THERMAL ADVECTION BECOMES MORE NEUTRAL THEREFORE WHILE AT LEAST SOME CLOUDS WILL DEVELOP THEY SHOULD TEND TO FLATTEN OUT QUICKLY THROUGH THE AFTERNOON AND EARLY EVENING AS SOME ADDITIONAL DRYING IS NOTED IN THE FORECAST SOUNDINGS MAINLY ABOVE 6,000 FEET. THE CYCLONIC FLOW ALOFT CONTINUES FRIDAY, ALTHOUGH THE LOW-LEVEL FLOW APPEARS TO BECOME A BIT MORE ANTICYCLONIC. THIS WILL ALLOW THE PRESSURE GRADIENT TO RELAX FRIDAY AND FRIDAY NIGHT, ALTHOUGH THE FORECAST SOUNDINGS DO INDICATE ENOUGH VERTICAL MIXING OCCURS YET AGAIN FRIDAY FOR POTENTIALLY BREEZY CONDITIONS. MUCH BETTER DECOUPLING THEN TAKES PLACE FRIDAY NIGHT AS A SURFACE HIGH BEGINS TO SETTLE IN AND THE CLOSED SLOW SHIFTS EAST. FOR SATURDAY, HIGH PRESSURE FROM SOUTHEASTERN CANADA SETTLES OVER THE AREA AS MIDLEVEL RIDGING ARRIVES FROM THE WEST. THE PATTERN LOOKS FAIRLY PROGRESSIVE THEREFORE THE SURFACE HIGH WILL BEGIN SHIFTING OFFSHORE TOWARD EVENING. LIGHTER WINDS WITH NO SIGNIFICANT WEATHER EXPECTED, ALTHOUGH EITHER A SEA BREEZE DEVELOPS OR MERGES WITH THE LOW-LEVEL FLOW EVENTUALLY SHIFTING FROM A SOUTHERLY DIRECTION. AS FOR TEMPERATURES, WE MOSTLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE GFS AND NAM MOS WITH JUST SOME MINOR ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE CWA ARRIVES DURING THE START OF THIS TIME FRAME. MOISTURE FROM THE REMNANTS OF TROPICAL STORM HERMINE MAY GET CAUGHT UP WITH A COLD FRONT AND UPPER-LEVEL TROUGH ADVANCING FROM THE NORTHERN/CENTRAL PLAINS. AS THE UPPER-LEVEL TROUGH INITIALLY AMPLIFIES ACROSS THE PLAINS, ANY TRAPPED MOISTURE SHOULD BE PULLED NORTHWARD. DOWNSTREAM THOUGH, RIDGING WILL BE ENHANCED ALTHOUGH GIVEN THE AMPLIFICATION OF THE PATTERN EVERYTHING SHOULD BE PROGRESSIVE. DESPITE THE LARGE TROUGH FORECAST TO BE EXITING THE EAST COAST, THE STRENGTH OF THE INCOMING TROUGH SHOULD BE ENOUGH TO PUSH THE RIDGE EASTWARD WITH TIME. THERE ARE SOME TIMING DIFFERENCES REGARDING THE ARRIVAL OF THE POTENTIAL SHOWERS/STORMS, AS THE NAM/WRF IS BELIEVED TO BE TO SLOW GIVEN THE PATTERN WHILE THE GFS/ECMWF ARE PROBABLY TO FAST. THE FASTER MODEL SOLUTIONS APPEAR TO HAVE THE STRONGEST LOW TO MID LEVEL THETA-E ADVECTION LAGGING BEHIND THE QPF. THEREFORE, MADE SOME TIMING ADJUSTMENTS TO THE POPS SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE POPS WILL REMAIN IN THE CHC CATEGORY FOR NOW, AND THE REGION REALLY DOES NEED THE RAIN AND THIS LOOKS LIKE OUR BEST CHC SINCE WEEKS AGO. IT WILL BE INTERESTING REGARDING HOW MUCH PRECIPITATION OCCURS WITH THIS SYSTEM AS MUCH OF THE MODEL GUIDANCE HAS THE UPPER-LEVEL TROUGH DEAMPLIFYING AS IT MOVES EASTWARD. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SURFACE HIGH PRESSURE FOLLOWS FOR MONDAY WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SOUTHEASTWARD FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SOME SHOWERS TUESDAY INTO WEDNESDAY, THEN HIGH PRESSURE NEAR THE MIDWEST BEGINS TO SLIDE EASTWARD TOWARD THE MID ATLANTIC DURING WEDNESDAY. THERE ARE NO REAL LARGE RIDGES FORECAST TO BE PERSISTENT AS THE NORTHERN STREAM LOOKS TO DOMINATE, THUS NO EXCESSIVE HEAT IS ANTICIPATED DURING THIS ENTIRE TIME FRAME. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE TAF PERIOD EVEN THOUGH A DECK OF BROKEN STRATOCUMULUS IS EXPECTED OVER OUR REGION FOR MUCH OF THE AFTERNOON INTO THE EARLY EVENING. THAT DECK WAS ALREADY PUSHING INTO THE NORTHWESTERN TAF SITES LATE THIS MORNING. THE CLOUD BASES SHOULD BE 5000 FEET OR GREATER. THE MAIN WEATHER IMPACT TODAY WILL BE THE WIND. A WEST NORTHWEST WIND AROUND 15 KNOTS WILL DEVELOP THIS MORNING AND IT SHOULD CONTINUE INTO THE EARLY EVENING. WIND GUSTS INTO THE 20S ARE LIKELY. AFTER SUNSET, AROUND 2300Z, WIND SPEEDS ARE FORECAST TO DIMINISH. OUTLOOK... HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER CONDITIONS FROM TONIGHT INTO SATURDAY. A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO BRING SHOWERS TO OUR REGION FROM LATE SATURDAY NIGHT INTO SUNDAY NIGHT. DRY WEATHER SHOULD RETURN FOR MONDAY. && .MARINE... 44065, A FEW OF THE DELAWARE BAY OBSERVATIONS AND, MOST RECENTLY, 44009 HAVE BEEN GUSTING TO 25 KT THIS MORNING. GUIDANCE SHOWS NO CLEAR TREND DOWNWARD TODAY, AND THE AIR TEMPERATURES EVENTUALLY WILL EXCEED THE WATER TEMPERATURES BY ONLY A FEW DEGREES. GIVEN ALL THIS, WE`VE PUT UP AN ADVISORY THAT WILL RUN INTO THE EVENING. AFTER THAT, WHILE THE WIND SHOULD REMAIN GUSTY INTO FRIDAY, IT APPEARS AS THOUGH GUSTS WILL STAY AROUND 20 KNOTS ON THE WATER BEFORE BEGINNING TO DIMINISH IN EARNEST. A FRONTAL BOUNDARY IS FORECAST TO APPROACH FROM THE WEST AND IT IS EXPECTED TO ARRIVE ON SUNDAY. IT DOES NOT APPEAR AS THOUGH THE PRESSURE GRADIENT IN THE VICINITY OF THE FRONT WILL PRODUCE WIND GUSTS IN EXCESS OF ABOUT 20 KNOTS. HIGH PRESSURE SHOULD FOLLOW FOR MONDAY. && .FIRE WEATHER... THE RATHER DRY CONDITIONS WILL CONTINUE AS THE FINE FUELS ARE EXCEPTIONALLY DRY. A NORTHWESTERLY WIND WILL BE GUSTY TODAY, AS FORECAST SOUNDINGS INDICATE A DEEPENING BOUNDARY LAYER WITH GUST POTENTIAL ABOUT 25 KNOTS. WHILE MOST AREAS WILL PROBABLY HIT THE WIND CRITERIA TODAY, THE LIMITING FACTOR WILL BE THE RELATIVE HUMIDITY VALUES. THE DEW POINTS WILL GENERALLY BE IN THE 40S TODAY, HOWEVER THE AIR TEMPERATURES WILL BE MUCH COOLER COMPARED TO YESTERDAY. THIS WILL TEND TO KEEP THE RELATIVE HUMIDITY VALUES UP. DESPITE THIS, THERE WILL STILL BE AN ENHANCED FIRE DANGER TODAY. SINCE ALL THE CRITERIA LOOKS NOT TO BE MET, WE WILL HOLD OFF ON ANY RED FLAG WARNINGS AND HIGHLIGHT THIS ENHANCED DANGER FOR MOST AREAS IN THE HAZARDOUS WEATHER OUTLOOK AND THE FIRE WEATHER FORECAST. A SPECIAL WEATHER STATEMENT /SPS/ MAY BE ISSUED LATER TO HIGHLIGHT THE ENHANCED RISK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE NEAR TERM...GORSE/KLINE SHORT TERM...GORSE LONG TERM...GORSE/O`HARA AVIATION...DELISI/IOVINO MARINE...DELISI/IOVINO FIRE WEATHER...GORSE 000 FXUS61 KPHI 091401 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1001 AM EDT THU SEP 9 2010 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL REMAIN NEAR NORTHERN NEW ENGLAND TODAY, THEN GRADUALLY SHIFT EASTWARD TONIGHT AND FRIDAY. MEANWHILE, HIGH PRESSURE OVER THE MIDWEST WILL SLOWLY SHIFT EASTWARD THROUGH FRIDAY NIGHT, EVENTUALLY SETTLING OVER OUR AREA SATURDAY. THIS HIGH PRESSURE SYSTEM WILL THEN MOVE OFFSHORE LATE SATURDAY. A COLD FRONT WILL CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT SLIDES THROUGH LATE TUESDAY, THEN HIGH PRESSURE BEGINS TO BUILD TOWARD OUR AREA WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A 06Z SURFACE ANALYSIS PLACED A COLD FRONT OFF THE COAST OF NEW ENGLAND AND THE MID ATLANTIC THEN BACK DOWN INTO THE GULF COAST STATES. HIGH PRESSURE WAS SITUATED FROM THE WESTERN GREAT LAKES TO CENTRAL CANADA. AN UPPER AIR ANALYSIS PLACED A CLOSED LOW OVER NORTHERN NEW ENGLAND WITH SEVERAL SHORT WAVES ROTATING AROUND IT. A 300 MB JET WAS LOCATED FROM THE UPPER GREAT LAKES TO THE MID ATLANTIC REGION. OUR WEATHER TODAY WILL BE CONTROLLED BY A STRONG CLOSED LOW ANCHORED NEAR NORTHERN NEW ENGLAND WITH CYCLONIC FLOW OCCURRING ACROSS THE MID ATLANTIC AND NORTHEAST. A NORTHWESTERLY FLOW OF COOLER AIR WILL COMBINE WITH A TIGHTENED PRESSURE GRADIENT TO PRODUCE BREEZY TO WINDY CONDITIONS. THE WINDS HAVE DIMINISHED HOWEVER AS DAYTIME HEATING OCCURS, THE BOUNDARY LAYER MIXING WILL DEEPEN WITH TIME ALLOWING FOR BETTER VERTICAL MIXING. IF WE MIX TO THE FULL POTENTIAL, WE WOULD BE ABLE TO TAP SOME 25 KNOTS OF WIND. THEREFORE, WE WILL CONTINUE TO CARRY INCREASED WINDS THROUGH THE DAY, BEFORE SOME DROPPING OFF IS EXPECTED TOWARD SUNSET AS THE LOSS OF DAYTIME HEATING OCCURS. THE CYCLONIC FLOW COUPLED WITH CAA AND ADDED MOISTURE FROM THE GREAT LAKES CONTINUES TO GENERATE A WEALTH OF STRATOCUMULUS TO OUR NORTHWEST. AN AREA OF CHANNELIZED VORTICITY IS LIKELY ENHANCING THIS CLOUD COVER, AND THIS VORTICITY IS FORECAST TO BE MAINTAINED THROUGH TODAY AND EVEN SETTLE SOUTHWARD SOME. THIS WILL TEND TO KEEP CLOUDS MORE CONCENTRATED THE FARTHER NORTH ONE GOES. THE FORECAST CHALLENGE TODAY IS HOW MUCH IN THE WAY OF STRATOCUMULUS CAN EITHER BE PULLED INTO OUR AREA OR FORM. THE FORECAST SOUNDINGS HAVE A HINT OF A LITTLE INSTABILITY DEVELOPING THIS AFTERNOON AS BOUNDARY LAYER MIXING IS MAXIMIZED. THIS SHALLOW RIBBON OF INSTABILITY IS WHERE THE CLOUDS WOULD BE AND THIS POINTS MAINLY ACROSS OUR NORTHERN ZONES. FARTHER SOUTH, THE CHANNELIZED VORTICITY IS FORECAST TO ARRIVE MUCH LATER IN THE DAY AND THE AIR MASS IS ACTUALLY DRIER WITH MORE OF A CAP. THE FLY IN THE OINTMENT WOULD BE IF CLOUDS DEVELOP SINCE THE CONVECTIVE TEMPERATURES SHOULD BE REACHED AND THE MOISTURE BECOMES TRAPPED UNDER THE INVERSION. WE ARE LEANING TOWARD THIS AND FOR NOW WE INCREASED THE SKY COVER SOME BUT STILL MAINTAINED MORE COVERAGE UP NORTH COMPARED TO DOWN SOUTH. THE NORTHWESTERLY FLOW IS GENERATING LAKE EFFECT RAIN SHOWERS ACROSS WESTERN AND CENTRAL NEW YORK. THE TRAJECTORY WOULD FAVOR THIS BEING PUSHED TOWARD NORTHEASTERN PENNSYLVANIA, AND THIS COULD BE HELPED TO SOME EXTENT BY THE CHANNELIZED VORTICITY. SINCE THIS ACTIVITY WOULD BE MOVING FARTHER AWAY FROM ITS MAIN MOISTURE SOURCE /LAKES ONTARIO AND ERIE/, PERHAPS A LIGHT SHOWER OR SOME SPRINKLES GET TO THE SOUTHERN POCONOS AND FAR NORTHWESTERN NEW JERSEY. AM NOT REAL CONFIDENT IF MEASURABLE PRECIPITATION OCCURS, THEREFORE WILL GO WITH POPS BELOW 15 PERCENT AND ADD A CHC OF SPRINKLES FOR NOW. AS FOR TEMPERATURES, WE GENERALLY SIDED WITH A BLEND OF THE GFS/NAM MOS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE LARGE CLOSED LOW OVER NEW ENGLAND IS FORECAST TO SLIDE SOUTHWARD TONIGHT, PUSHING THE CHANNELIZED VORTICITY THROUGH THE NORTHERN MID ATLANTIC REGION. THE GFS ACTUALLY HAS A MORE FOCUSED SHORT WAVE ROTATING AROUND THE CLOSED LOW, WHILE SOME OF THE OTHER GUIDANCE IS MORE CHANNELIZED. WE ARE NOT ANTICIPATING ANY PRECIPITATION WITH THIS, HOWEVER IT MAY IMPACT THE CLOUD COVER FORECAST. THERE SHOULD BE A FAIR AMOUNT OF STRATOCUMULUS AROUND IN THE EVENING WITH MORE UP NORTH COMPARED TO THE DELMARVA. WITH THE LOSS OF DAYTIME HEATING, THE STRATOCUMULUS SHOULD TEND TO FLATTEN OUT AND DISSIPATE FROM SOUTH TO NORTH. THE NORTHERN ZONES SHOULD TEND TO HOLD ONTO MORE IN THE WAY CLOUDS LONGER GIVEN THE CLOSER PROXIMITY OF THE CLOSED LOW AND THE NORTHWESTERLY FLOW OFF THE EASTERN GREAT LAKES. WHILE THE PRESSURE GRADIENT IS FORECAST TO REMAIN TIGHTENED TONIGHT ALONG WITH SOME CAA, WE SHOULD BE ABLE TO DECOUPLE MORE QUICKLY AS THE LOW-LEVEL FLOW IS WEAKER AND THE BOUNDARY LAYER BECOMES MORE SHALLOW AND COOLS. FOR FRIDAY, THE THERMAL ADVECTION BECOMES MORE NEUTRAL THEREFORE WHILE AT LEAST SOME CLOUDS WILL DEVELOP THEY SHOULD TEND TO FLATTEN OUT QUICKLY THROUGH THE AFTERNOON AND EARLY EVENING AS SOME ADDITIONAL DRYING IS NOTED IN THE FORECAST SOUNDINGS MAINLY ABOVE 6,000 FEET. THE CYCLONIC FLOW ALOFT CONTINUES FRIDAY, ALTHOUGH THE LOW-LEVEL FLOW APPEARS TO BECOME A BIT MORE ANTICYCLONIC. THIS WILL ALLOW THE PRESSURE GRADIENT TO RELAX FRIDAY AND FRIDAY NIGHT, ALTHOUGH THE FORECAST SOUNDINGS DO INDICATE ENOUGH VERTICAL MIXING OCCURS YET AGAIN FRIDAY FOR POTENTIALLY BREEZY CONDITIONS. MUCH BETTER DECOUPLING THEN TAKES PLACE FRIDAY NIGHT AS A SURFACE HIGH BEGINS TO SETTLE IN AND THE CLOSED SLOW SHIFTS EAST. FOR SATURDAY, HIGH PRESSURE FROM SOUTHEASTERN CANADA SETTLES OVER THE AREA AS MIDLEVEL RIDGING ARRIVES FROM THE WEST. THE PATTERN LOOKS FAIRLY PROGRESSIVE THEREFORE THE SURFACE HIGH WILL BEGIN SHIFTING OFFSHORE TOWARD EVENING. LIGHTER WINDS WITH NO SIGNIFICANT WEATHER EXPECTED, ALTHOUGH EITHER A SEA BREEZE DEVELOPS OR MERGES WITH THE LOW-LEVEL FLOW EVENTUALLY SHIFTING FROM A SOUTHERLY DIRECTION. AS FOR TEMPERATURES, WE MOSTLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE GFS AND NAM MOS WITH JUST SOME MINOR ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE CWA ARRIVES DURING THE START OF THIS TIME FRAME. MOISTURE FROM THE REMNANTS OF TROPICAL STORM HERMINE MAY GET CAUGHT UP WITH A COLD FRONT AND UPPER-LEVEL TROUGH ADVANCING FROM THE NORTHERN/CENTRAL PLAINS. AS THE UPPER-LEVEL TROUGH INITIALLY AMPLIFIES ACROSS THE PLAINS, ANY TRAPPED MOISTURE SHOULD BE PULLED NORTHWARD. DOWNSTREAM THOUGH, RIDGING WILL BE ENHANCED ALTHOUGH GIVEN THE AMPLIFICATION OF THE PATTERN EVERYTHING SHOULD BE PROGRESSIVE. DESPITE THE LARGE TROUGH FORECAST TO BE EXITING THE EAST COAST, THE STRENGTH OF THE INCOMING TROUGH SHOULD BE ENOUGH TO PUSH THE RIDGE EASTWARD WITH TIME. THERE ARE SOME TIMING DIFFERENCES REGARDING THE ARRIVAL OF THE POTENTIAL SHOWERS/STORMS, AS THE NAM/WRF IS BELIEVED TO BE TO SLOW GIVEN THE PATTERN WHILE THE GFS/ECMWF ARE PROBABLY TO FAST. THE FASTER MODEL SOLUTIONS APPEAR TO HAVE THE STRONGEST LOW TO MID LEVEL THETA-E ADVECTION LAGGING BEHIND THE QPF. THEREFORE, MADE SOME TIMING ADJUSTMENTS TO THE POPS SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE POPS WILL REMAIN IN THE CHC CATEGORY FOR NOW, AND THE REGION REALLY DOES NEED THE RAIN AND THIS LOOKS LIKE OUR BEST CHC SINCE WEEKS AGO. IT WILL BE INTERESTING REGARDING HOW MUCH PRECIPITATION OCCURS WITH THIS SYSTEM AS MUCH OF THE MODEL GUIDANCE HAS THE UPPER-LEVEL TROUGH DEAMPLIFYING AS IT MOVES EASTWARD. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SURFACE HIGH PRESSURE FOLLOWS FOR MONDAY WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SOUTHEASTWARD FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SOME SHOWERS TUESDAY INTO WEDNESDAY, THEN HIGH PRESSURE NEAR THE MIDWEST BEGINS TO SLIDE EASTWARD TOWARD THE MID ATLANTIC DURING WEDNESDAY. THERE ARE NO REAL LARGE RIDGES FORECAST TO BE PERSISTENT AS THE NORTHERN STREAM LOOKS TO DOMINATE, THUS NO EXCESSIVE HEAT IS ANTICIPATED DURING THIS ENTIRE TIME FRAME. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE TAF PERIOD EVEN THOUGH A DECK OF BROKEN STRATOCUMULUS IS EXPECTED OVER OUR REGION FOR MUCH OF THE AFTERNOON INTO THE EARLY EVENING. THAT DECK WAS ALREADY PUSHING INTO THE NORTHWESTERN TAF SITES LATE THIS MORNING. THE CLOUD BASES SHOULD BE 5000 FEET OR GREATER. THE MAIN WEATHER IMPACT TODAY WILL BE THE WIND. A WEST NORTHWEST WIND AROUND 15 KNOTS WILL DEVELOP THIS MORNING AND IT SHOULD CONTINUE INTO THE EARLY EVENING. WIND GUSTS INTO THE 20S ARE LIKELY. AFTER SUNSET, AROUND 2300Z, WIND SPEEDS ARE FORECAST TO DIMINISH. OUTLOOK... HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER CONDITIONS FROM TONIGHT INTO SATURDAY. A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO BRING SHOWERS TO OUR REGION FROM LATE SATURDAY NIGHT INTO SUNDAY NIGHT. DRY WEATHER SHOULD RETURN FOR MONDAY. && .MARINE... 44065, A FEW OF THE DELAWARE BAY OBSERVATIONS AND, MOST RECENTLY, 44009 HAVE BEEN GUSTING TO 25 KT THIS MORNING. GUIDANCE SHOWS NO CLEAR TREND DOWNWARD TODAY, AND THE AIR TEMPERATURES EVENTUALLY WILL EXCEED THE WATER TEMPERATURES BY ONLY A FEW DEGREES. GIVEN ALL THIS, WE`VE PUT UP AN ADVISORY THAT WILL RUN INTO THE EVENING. AFTER THAT, WHILE THE WIND SHOULD REMAIN GUSTY INTO FRIDAY, IT APPEARS AS THOUGH GUSTS WILL STAY AROUND 20 KNOTS ON THE WATER BEFORE BEGINNING TO DIMINISH IN EARNEST. A FRONTAL BOUNDARY IS FORECAST TO APPROACH FROM THE WEST AND IT IS EXPECTED TO ARRIVE ON SUNDAY. IT DOES NOT APPEAR AS THOUGH THE PRESSURE GRADIENT IN THE VICINITY OF THE FRONT WILL PRODUCE WIND GUSTS IN EXCESS OF ABOUT 20 KNOTS. HIGH PRESSURE SHOULD FOLLOW FOR MONDAY. && .FIRE WEATHER... THE RATHER DRY CONDITIONS WILL CONTINUE AS THE FINE FUELS ARE EXCEPTIONALLY DRY. A NORTHWESTERLY WIND WILL BE GUSTY TODAY, AS FORECAST SOUNDINGS INDICATE A DEEPENING BOUNDARY LAYER WITH GUST POTENTIAL ABOUT 25 KNOTS. WHILE MOST AREAS WILL PROBABLY HIT THE WIND CRITERIA TODAY, THE LIMITING FACTOR WILL BE THE RELATIVE HUMIDITY VALUES. THE DEW POINTS WILL GENERALLY BE IN THE 40S TODAY, HOWEVER THE AIR TEMPERATURES WILL BE MUCH COOLER COMPARED TO YESTERDAY. THIS WILL TEND TO KEEP THE RELATIVE HUMIDITY VALUES UP. DESPITE THIS, THERE WILL STILL BE AN ENHANCED FIRE DANGER TODAY. SINCE ALL THE CRITERIA LOOKS NOT TO BE MET, WE WILL HOLD OFF ON ANY RED FLAG WARNINGS AND HIGHLIGHT THIS ENHANCED DANGER FOR MOST AREAS IN THE HAZARDOUS WEATHER OUTLOOK AND THE FIRE WEATHER FORECAST. A SPECIAL WEATHER STATEMENT /SPS/ MAY BE ISSUED LATER TO HIGHLIGHT THE ENHANCED RISK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...GORSE/O`HARA AVIATION...DELISI/IOVINO MARINE...DELISI/IOVINO FIRE WEATHER...GORSE [top] 000 FXUS61 KAKQ 091356 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 956 AM EDT THU SEP 9 2010 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE MID ATLANTIC REGION FROM THE NORTH THROUGH FRIDAY. THE HIGH WILL SLIDE OFF THE COAST ON SATURDAY... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... TODAY...DEEP-LAYER RIDGING WILL CONTINUE TO BUILD ACROSS THE MID ATLC REGION...IN BETWEEN THE UPR LOW OVER NRN NEW ENGLAND AND RIDGE AXIS OVER THE CENTRAL CONUS. THIS WILL LEAD TO CONTINUED DRYING CONDITIONS AND MSTLY SUNNY SKIES ACROSS THE REGION...THOUGH GIVEN THE DEEP NW FLOW AND EARLY-SEASON INSTBY OVER THE WRN GREAT LAKES...CANNOT RULE OUT SCT TO OCNLY BKN LAKE-ORIGINATED CU ADVECTING ALL THE WAY INTO THE LWR MD ERN SHORE. IN THIS REGION... EXPECT MORE OF A FLUCTUATION WITH THE CLOUD COVER DURING THE AFTN (MSTLY-PTLY SUNNY)...WHICH WOULD HAVE AN IMPACT ON TEMPS. FOR NOW...HAVE STUCK WITH HIGHS IN THE UPR 70S OVER THE LWR MD ERN SHORE...HOWEVER THE LATEST GUIDANCE (INCLUDING THE MOST RECENT LAMP OR LAV GUIDANCE) WOULD SUGGEST MID 70S TOPS. ELSEWHERE...LOCAL 1000-850 MB THICKNESS GUIDANCE SUPPORTS HIGHS 80-85F...HIGHEST S/W OF A FVX-PTB-FKN LINE. OF GREATER CONCERN WILL AGAIN BE THE INCREASED FIRE DANGER. WILL CONTINUE WITH THE SPS OVER INLAND AREAS (W OF CHES BAY)...AS AGAIN EXPECT MIN RH`S IN THE 20-25 PCT RANGE. SUSTAINED WINDS WILL BE TOO LIGHT TO JUSTIFY RED FLAG WARNINGS (AROUND 10-12 MPH)...HOWEVER AGAIN EXPECT A FAIRLY GOOD GUST FACTOR TODAY WITH THE DEEPENING MIXED LAYER (GUSTS 20-25 MPH). OVER THE LWR ERN SHORE...WINDS WILL BE STRONGER (MORE LIKE 15-20 MPH WITH GUSTS TO 30)...HOWEVER AT THE SAME TIME RH`S WILL BE HIGHER IN THIS REGION (30-40%) GIVEN MORE STRATO-CU CLOUD COVER AND WITH THE SLIGHT INCREASE IN LLVL MSTR AS LLVL WINDS CROSS CHES BAY. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... FEW CHANGES MADE TO THE PREVIOUS FCSTS. AS THE SFC HIGH CONTINUES TO BUILD INTO THE MID ATLC REGION TONIGHT...SFC WINDS MAY HAVE A TOUGH TIME DECOUPLING OVER MUCH OF THE FCST AREA (ESPECIALLY DOWNWIND OF CHES BAY). THEREFORE...EXPECT THE DEGREE OF RADIATIONAL COOLING TO BE LIMITED SOMEWHAT TONIGHT...THUS OPTED TO NOT UNDERCUT MOS BLEND TEMPS FOR TONIGHT. ANOTHER NICE DAY ON FRI...WITH THE LLVL THICKNESS PROFILES GIVEN MOSTLY SUNNY CONDITIONS SUPPORTING HIGHS IN THE MID 70S LWR MD ERN SHORE AND FROM THE UPR 70S TO LWR 80S FROM NE-SW ACROSS THE REST OF THE REGION. SURFACE HIGH PRESSURE WILL LIKELY REMAIN OVER THE REGION FOR DRY WEATHER AGAIN ON SATURDAY. HOWEVER...THE NEXT SYSTEM WILL LIKELY BRING SOME CLOUDS TO THE AREA LATE IN THE DAY. MODELS KEEP PRECIP WEST OF OUR AREA THROUGH SATURDAY AFTERNOON...SO WILL CONTINUE WITH A DRY FORECAST FOR NOW. HIGH TEMPS WILL BE IN THE LOW/MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT APPROACHES FROM THE WEST SATURDAY NIGHT AND SUNDAY. CLOUDS WILL INCREASE AHEAD OF THE FRONT WITH A CHANCE FOR SHOWERS SUNDAY ALONG WITH THE POSSIBILITY OF THUNDER DURING THE AFTERNOON AND EVENING. CLOUD COVER SHOULD HOLD MAXIMUM TEMPERATURES IN THE LOW TO MID 80S. THE COLD FRONT CLEARS THE COAST LATER SUNDAY NIGHT WITH DRY AND MILD CONDITIONS PREVAILING EARLY NEXT WEEK WITH HIGH TEMPERATURES REMAINING THE LOW TO MID 80S...AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S. ANOTHER COLD FRONT APPROACHES THE MIDDLE OF NEXT WEEK WITH LITTLE INDICATION OF ANY MOISTURE. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... HI PRES WILL BLD INTO AND OVR THE REGION FOR TDY INTO SAT. THIS WILL RESULT IN VFR CONDITIONS CONTINUING OVR THE AREA. FOR TDY INTO FRI MORNG...EXPECT NW OR N WNDS 10 TO 20 MPH THIS AFTN WITH STRNGEST WNDS AT SBY. LWR CIGS/VSBYS POSSIBLE LATE SAT NGT THRU SUN...WHEN NEXT COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... WILL MAINTAIN SCA FOR THE CHES BAY AND NRN TWO CSTL ZNS THRU 7 AM THIS MORNG...DUE TO GUSTY NW OR N WNDS BEHIND THE FRNT. THEN...THE MIXING PROFILE BECOMES MORE STABLE OVR THE WATER DURING TDY. ANOTHER NW OR NW WND SURGE ARRIVES TNGT. IT IS NOT QUITE AS STRONG...AND WNDS SHUD REMAIN JUST BELOW SCA CONDITIONS. HI PRES WILL BLD OVR THE AREA FRI INTO SAT...WITH ANOTHER COLD FRNT APPROACHING AND MOVNG THRU SUN. && .FIRE WEATHER... AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER TODAY COMPARED TO WED... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS EXPECTED...WILL AGAIN HIGHLIGHT THE THREAT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON IN A SPECIAL WEATHER STATEMENT. THIS STATEMENT WILL INCLUDE ALL OF OUR COUNTIES IN VA EXCEPT FAR SE VA AND THE LOWER EASTERN SHORE. IT WILL ALSO INCLUDE THE LOWER MD EASTERN SHORE. AN ADDITIONAL STATEMENT MAY BE NECESSARY FOR FRIDAY AS CONDITIONS ARE EXPECTED TO BE SIMILAR TO THURSDAY. && .CLIMATE... WITH TODAY`S HIGH OF 90 F AT RICHMOND...THERE HAVE NOW BEEN 71 DAYS THIS YEAR WITH A HIGH OF 90 F OR HIGHER. THIS IS THE MOST ON RECORD AT RIC...SURPASSING THE 70 DAYS OF 90+ BACK IN 1977. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...BKH/JDM NEAR TERM...BKH/JDM SHORT TERM...BKH/JDM LONG TERM...AJZ AVIATION...TMG MARINE...TMG FIRE WEATHER... CLIMATE... [top] 000 FXUS61 KLWX 091312 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 912 AM EDT THU SEP 9 2010 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL PERSIST ACROSS THE MID ATLANTIC THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY...WITH HIGH PRESSURE RETURNING MONDAY. A SECOND COLD FRONT IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AN UPPER-LEVEL LOW WILL SLOWLY PASS THROUGH MAINE THIS AFTERNOON WHILE CANADIAN HIGH PRESSURE BUILDS TOWARD THE MID-ATLANTIC. A NORTHWEST FLOW BETWEEN THESE SYSTEMS WILL CONTINUE TO BRING DRY CONDITIONS...BUT IT WILL BE NOTICEABLY COOLER WITH MAX TEMPS GENERALLY IN THE 70S AND LOWER 80S ACROSS MOST LOCATIONS...BUT COOLER IN THE MOUNTAINS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... CANADIAN HIGH PRESSURE WILL BUILD OVER THE REGION FOR TONIGHT THROUGH FRIDAY...BRINGING MORE DRY AND COOL CONDITIONS. MAX TEMPS FRIDAY WILL RANGE FROM THE 60S IN THE MOUNTAINS TO THE 70S ACROSS MOST OTHER LOCATIONS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A RIDGE OF HIGH PRESSURE OVER THE REGION FRIDAY NIGHT WILL SLOWLY MOVE OFFSHORE SATURDAY. A WARM FRONT WILL MOVE NORTH ACROSS THE MID ATLANTIC WHILE A COLD FRONT MOVES EAST ACROSS THE OHIO VALLEY. THE COLD FRONT SHOULD MOVE THROUGH THE CWFA DURING THE DAY ON SUNDAY...BRINGING A CHANCE OF MUCH NEEDED PRECIPITATION. DIDN`T MAKE ANY CHANGES TO THE POPS FOR NOW...BUT MAY HAVE TO EVENTUALLY INCREASE THEM AS THE TIMING AND STRENGTH OF THE FRONT BECOME CLEARER. HIGH PRESSURE BUILDS BRIEFLY ON MONDAY...WITH ANOTHER COLD FRONT EXPECTED FOR THE MIDDLE OF THE WEEK. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... NORTHWEST WINDS WILL GUST AROUND 20-25 KNOTS LATE THIS MORNING THROUGH THIS AFTERNOON. A SCT CU DECK AROUND 6-8KFT IS EXPECTED THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING AND VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. BREEZY NW WINDS WILL CONTINUE THROUGH FRIDAY AFTERNOON. SUB VFR CIGS/VSBYS POSSIBLE SATURDAY INTO SUNDAY AS A COLD FRONT CROSS THE AREA...ACCOMPANIED BY SCT CONVECTION. NW WINDS EXPECTED BEHIND THE FRONT. && .MARINE... A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL OF THE WATERS THROUGH 6 PM FOR NORTHWEST WINDS GUSTING AROUND 20-25 KNOTS. AN SCA WILL CONTINUE FOR TONIGHT FOR THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC. NW WINDS WILL CONTINUE ACROSS THE WATERS THROUGH FRIDAY AFTERNOON...AND TURN MORE NORTHERLY FRIDAY NIGHT. SMALL CRAFT CONDITIONS WILL CONTINUE THROUGH FRIDAY AFTERNOON...BUT DO EXPECT GUSTINESS TO DIMINISH AS AN UPPER LOW PUSHES EAST LATE FRIDAY INTO EARLY SATURDAY. A COLD FRONT WILL MOVE ACROSS THE WATERS ON SUNDAY...FOLLOWED BY HIGH PRESSURE ON MONDAY. && .FIRE WEATHER... RECENT DRY SPELL HAS LEAD TO LOW FUEL MOISTURE ACROSS THE AREA. NORTHWEST WINDS WILL BE SUSTAINED AROUND 10 TO 15 MPH WITH FREQUENT GUSTS AROUND 20 TO 25 MPH. THE STRONGEST WINDS WILL BE ACROSS NORTHERN MARYLAND. THE RELATIVE HUMIDITY WILL DROP TO 25-30 PERCENT ACROSS MOST LOCATIONS...BUT RH VALUES WILL BE A BIT HIGHER ACROSS THE RIDGE TOPS. THE GUSTY WINDS...LOW FUEL MOISTURE...AND LOW RELATIVE HUMIDITY WILL POSE AN ENHANCED THREAT FOR THE SPREAD OF WILDFIRES THIS AFTERNOON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ530>534- 537>543. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ535- 536. && $$ SYNOPSIS...NWL NEAR TERM...BJL SHORT TERM...GMS/BJL LONG TERM...NWL AVIATION...GMS/BJL MARINE...GMS/BJL FIRE WEATHER...BJL 000 FXUS61 KPHI 091032 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 632 AM EDT THU SEP 9 2010 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL REMAIN NEAR NORTHERN NEW ENGLAND TODAY, THEN GRADUALLY SHIFT EASTWARD TONIGHT AND FRIDAY. MEANWHILE, HIGH PRESSURE OVER THE MIDWEST WILL SLOWLY SHIFT EASTWARD THROUGH FRIDAY NIGHT, EVENTUALLY SETTLING OVER OUR AREA SATURDAY. THIS HIGH PRESSURE SYSTEM WILL THEN MOVE OFFSHORE LATE SATURDAY. A COLD FRONT WILL CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT SLIDES THROUGH LATE TUESDAY, THEN HIGH PRESSURE BEGINS TO BUILD TOWARD OUR AREA WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A 06Z SURFACE ANALYSIS PLACED A COLD FRONT OFF THE COAST OF NEW ENGLAND AND THE MID ATLANTIC THEN BACK DOWN INTO THE GULF COAST STATES. HIGH PRESSURE WAS SITUATED FROM THE WESTERN GREAT LAKES TO CENTRAL CANADA. AN UPPER AIR ANALYSIS PLACED A CLOSED LOW OVER NORTHERN NEW ENGLAND WITH SEVERAL SHORT WAVES ROTATING AROUND IT. A 300 MB JET WAS LOCATED FROM THE UPPER GREAT LAKES TO THE MID ATLANTIC REGION. OUR WEATHER TODAY WILL BE CONTROLLED BY A STRONG CLOSED LOW ANCHORED NEAR NORTHERN NEW ENGLAND WITH CYCLONIC FLOW OCCURRING ACROSS THE MID ATLANTIC AND NORTHEAST. A NORTHWESTERLY FLOW OF COOLER AIR WILL COMBINE WITH A TIGHTENED PRESSURE GRADIENT TO PRODUCE BREEZY TO WINDY CONDITIONS. THE WINDS HAVE DIMINISHED HOWEVER AS DAYTIME HEATING OCCURS, THE BOUNDARY LAYER MIXING WILL DEEPEN WITH TIME ALLOWING FOR BETTER VERTICAL MIXING. IF WE MIX TO THE FULL POTENTIAL, WE WOULD BE ABLE TO TAP SOME 25 KNOTS OF WIND. THEREFORE, WE WILL CONTINUE TO CARRY INCREASED WINDS THROUGH THE DAY, BEFORE SOME DROPPING OFF IS EXPECTED TOWARD SUNSET AS THE LOSS OF DAYTIME HEATING OCCURS. THE CYCLONIC FLOW COUPLED WITH CAA AND ADDED MOISTURE FROM THE GREAT LAKES CONTINUES TO GENERATE A WEALTH OF STRATOCUMULUS TO OUR NORTHWEST. AN AREA OF CHANNELIZED VORTICITY IS LIKELY ENHANCING THIS CLOUD COVER, AND THIS VORTICITY IS FORECAST TO BE MAINTAINED THROUGH TODAY AND EVEN SETTLE SOUTHWARD SOME. THIS WILL TEND TO KEEP CLOUDS MORE CONCENTRATED THE FARTHER NORTH ONE GOES. THE FORECAST CHALLENGE TODAY IS HOW MUCH IN THE WAY OF STRATOCUMULUS CAN EITHER BE PULLED INTO OUR AREA OR FORM. THE FORECAST SOUNDINGS HAVE A HINT OF A LITTLE INSTABILITY DEVELOPING THIS AFTERNOON AS BOUNDARY LAYER MIXING IS MAXIMIZED. THIS SHALLOW RIBBON OF INSTABILITY IS WHERE THE CLOUDS WOULD BE AND THIS POINTS MAINLY ACROSS OUR NORTHERN ZONES. FARTHER SOUTH, THE CHANNELIZED VORTICITY IS FORECAST TO ARRIVE MUCH LATER IN THE DAY AND THE AIRMASS IS ACTUALLY DRIER WITH MORE OF A CAP. THE FLY IN THE OINTMENT WOULD BE IF CLOUDS DEVELOP SINCE THE CONVECTIVE TEMPERATURES SHOULD BE REACHED AND THE MOISTURE BECOMES TRAPPED UNDER THE INVERSION. WE ARE LEANING TOWARD THIS AND FOR NOW WE INCREASED THE SKY COVER SOME BUT STILL MAINTAINED MORE COVERAGE UP NORTH COMPARED TO DOWN SOUTH. THE NORTHWESTERLY FLOW IS GENERATING LAKE EFFECT RAIN SHOWERS ACROSS WESTERN AND CENTRAL NEW YORK. THE TRAJECTORY WOULD FAVOR THIS BEING PUSHED TOWARD NORTHEASTERN PENNSYLVANIA, AND THIS COULD BE HELPED TO SOME EXTENT BY THE CHANNELIZED VORTICITY. SINCE THIS ACTIVITY WOULD BE MOVING FARTHER AWAY FROM ITS MAIN MOISTURE SOURCE /LAKES ONTARIO AND ERIE/, PERHAPS A LIGHT SHOWER OR SOME SPRINKLES GET TO THE SOUTHERN POCONOS AND FAR NORTHWESTERN NEW JERSEY. AM NOT REAL CONFIDENT IF MEASURABLE PRECIPITATION OCCURS, THEREFORE WILL GO WITH POPS BELOW 15 PERCENT AND ADD A CHC OF SPRINKLES FOR NOW. AS FOR TEMPERATURES, WE GENERALLY SIDED WITH A BLEND OF THE GFS/NAM MOS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE LARGE CLOSED LOW OVER NEW ENGLAND IS FORECAST TO SLIDE SOUTHWARD TONIGHT, PUSHING THE CHANNELIZED VORTICITY THROUGH THE NORTHERN MID ATLANTIC REGION. THE GFS ACTUALLY HAS A MORE FOCUSED SHORT WAVE ROTATING AROUND THE CLOSED LOW, WHILE SOME OF THE OTHER GUIDANCE IS MORE CHANNELIZED. WE ARE NOT ANTICIPATING ANY PRECIPITATION WITH THIS, HOWEVER IT MAY IMPACT THE CLOUD COVER FORECAST. THERE SHOULD BE A FAIR AMOUNT OF STRATOCUMULUS AROUND IN THE EVENING WITH MORE UP NORTH COMPARED TO THE DELMARVA. WITH THE LOSS OF DAYTIME HEATING, THE STRATOCUMULUS SHOULD TEND TO FLATTEN OUT AND DISSIPATE FROM SOUTH TO NORTH. THE NORTHERN ZONES SHOULD TEND TO HOLD ONTO MORE IN THE WAY CLOUDS LONGER GIVEN THE CLOSER PROXIMITY OF THE CLOSED LOW AND THE NORTHWESTERLY FLOW OFF THE EASTERN GREAT LAKES. WHILE THE PRESSURE GRADIENT IS FORECAST TO REMAIN TIGHTENED TONIGHT ALONG WITH SOME CAA, WE SHOULD BE ABLE TO DECOUPLE MORE QUICKLY AS THE LOW-LEVEL FLOW IS WEAKER AND THE BOUNDARY LAYER BECOMES MORE SHALLOW AND COOLS. FOR FRIDAY, THE THERMAL ADVECTION BECOMES MORE NEUTRAL THEREFORE WHILE AT LEAST SOME CLOUDS WILL DEVELOP THEY SHOULD TEND TO FLATTEN OUT QUICKLY THROUGH THE AFTERNOON AND EARLY EVENING AS SOME ADDITIONAL DRYING IS NOTED IN THE FORECAST SOUNDINGS MAINLY ABOVE 6,000 FEET. THE CYCLONIC FLOW ALOFT CONTINUES FRIDAY, ALTHOUGH THE LOW-LEVEL FLOW APPEARS TO BECOME A BIT MORE ANTICYCLONIC. THIS WILL ALLOW THE PRESSURE GRADIENT TO RELAX FRIDAY AND FRIDAY NIGHT, ALTHOUGH THE FORECAST SOUNDINGS DO INDICATE ENOUGH VERTICAL MIXING OCCURS YET AGAIN FRIDAY FOR POTENTIALLY BREEZY CONDITIONS. MUCH BETTER DECOUPLING THEN TAKES PLACE FRIDAY NIGHT AS A SURFACE HIGH BEGINS TO SETTLE IN AND THE CLOSED SLOW SHIFTS EAST. FOR SATURDAY, HIGH PRESSURE FROM SOUTHEASTERN CANADA SETTLES OVER THE AREA AS MIDLEVEL RIDGING ARRIVES FROM THE WEST. THE PATTERN LOOKS FAIRLY PROGRESSIVE THEREFORE THE SURFACE HIGH WILL BEGIN SHIFTING OFFSHORE TOWARD EVENING. LIGHTER WINDS WITH NO SIGNIFICANT WEATHER EXPECTED, ALTHOUGH EITHER A SEA BREEZE DEVELOPS OR MERGES WITH THE LOW-LEVEL FLOW EVENTUALLY SHIFTING FROM A SOUTHERLY DIRECTION. AS FOR TEMPERATURES, WE MOSTLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE GFS AND NAM MOS WITH JUST SOME MINOR ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE CWA ARRIVES DURING THE START OF THIS TIME FRAME. MOISTURE FROM THE REMNANTS OF TROPICAL STORM HERMINE MAY GET CAUGHT UP WITH A COLD FRONT AND UPPER-LEVEL TROUGH ADVANCING FROM THE NORTHERN/CENTRAL PLAINS. AS THE UPPER-LEVEL TROUGH INITIALLY AMPLIFIES ACROSS THE PLAINS, ANY TRAPPED MOISTURE SHOULD BE PULLED NORTHWARD. DOWNSTREAM THOUGH, RIDGING WILL BE ENHANCED ALTHOUGH GIVEN THE AMPLIFICATION OF THE PATTERN EVERYTHING SHOULD BE PROGRESSIVE. DESPITE THE LARGE TROUGH FORECAST TO BE EXITING THE EAST COAST, THE STRENGTH OF THE INCOMING TROUGH SHOULD BE ENOUGH TO PUSH THE RIDGE EASTWARD WITH TIME. THERE ARE SOME TIMING DIFFERENCES REGARDING THE ARRIVAL OF THE POTENTIAL SHOWERS/STORMS, AS THE NAM/WRF IS BELIEVED TO BE TO SLOW GIVEN THE PATTERN WHILE THE GFS/ECMWF ARE PROBABLY TO FAST. THE FASTER MODEL SOLUTIONS APPEAR TO HAVE THE STRONGEST LOW TO MID LEVEL THETA-E ADVECTION LAGGING BEHIND THE QPF. THEREFORE, MADE SOME TIMING ADJUSTMENTS TO THE POPS SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE POPS WILL REMAIN IN THE CHC CATEGORY FOR NOW, AND THE REGION REALLY DOES NEED THE RAIN AND THIS LOOKS LIKE OUR BEST CHC SINCE WEEKS AGO. IT WILL BE INTERESTING REGARDING HOW MUCH PRECIPITATION OCCURS WITH THIS SYSTEM AS MUCH OF THE MODEL GUIDANCE HAS THE UPPER-LEVEL TROUGH DEAMPLIFYING AS IT MOVES EASTWARD. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SURFACE HIGH PRESSURE FOLLOWS FOR MONDAY WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SOUTHEASTWARD FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SOME SHOWERS TUESDAY INTO WEDNESDAY, THEN HIGH PRESSURE NEAR THE MIDWEST BEGINS TO SLIDE EASTWARD TOWARD THE MID ATLANTIC DURING WEDNESDAY. THERE ARE NO REAL LARGE RIDGES FORECAST TO BE PERSISTENT AS THE NORTHERN STREAM LOOKS TO DOMINATE, THUS NO EXCESSIVE HEAT IS ANTICIPATED DURING THIS ENTIRE TIME FRAME. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AT 1030Z, THE SKY OVER OUR EIGHT TAF SITES WAS MOSTLY CLEAR AND THERE WERE NO VISIBILITY RESTRICTIONS. THE WIND WAS MAINLY FROM THE WEST AND NORTHWEST AT LESS THAN 10 KNOTS. VFR CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE TAF PERIOD EVEN THOUGH A DECK OF BROKEN STRATOCUMULUS IS EXPECTED OVER OUR REGION FOR MUCH OF THE AFTERNOON INTO THE EARLY EVENING. THE CLOUD BASES SHOULD BE 5000 FEET OR GREATER. THE MAIN WEATHER IMPACT TODAY WILL BE THE WIND. A WEST NORTHWEST WIND AROUND 15 KNOTS WILL DEVELOP THIS MORNING AND IT SHOULD CONTINUE INTO THE EARLY EVENING. WIND GUSTS INTO THE 20S ARE LIKELY. AFTER SUNSET, AROUND 2300Z, WIND SPEEDS ARE FORECAST TO DIMINISH. OUTLOOK... HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER CONDITIONS FROM TONIGHT INTO SATURDAY. A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO BRING SHOWERS TO OUR REGION FROM LATE SATURDAY NIGHT INTO SUNDAY NIGHT. DRY WEATHER SHOULD RETURN FOR MONDAY. && .MARINE... LOW PRESSURE WILL REMAIN OVER CANADA`S ATLANTIC PROVINCES AND THE ADJACENT WATERS INTO SATURDAY AS HIGH PRESSURE BUILDS INTO OUR REGION FROM THE WEST. WHILE THE WIND SHOULD REMAIN GUSTY INTO FRIDAY, IT APPEARS AS THOUGH GUSTS WILL STAY AROUND 20 KNOTS ON THE WATER SO WE SHOULD NOT NEED TO ISSUE A SMALL CRAFT ADVISORY. A FRONTAL BOUNDARY IS FORECAST TO APPROACH FROM THE WEST AND IT IS EXPECTED TO ARRIVE ON SUNDAY. IT DOES NOT APPEAR AS THOUGH THE PRESSURE GRADIENT IN THE VICINITY OF THE FRONT WILL PRODUCE WIND GUSTS IN EXCESS OF ABOUT 20 KNOTS. HIGH PRESSURE SHOULD FOLLOW FOR MONDAY. && .FIRE WEATHER... THE RATHER DRY CONDITIONS WILL CONTINUE AS THE FINE FUELS ARE EXCEPTIONALLY DRY. A NORTHWESTERLY WIND WILL BE GUSTY TODAY, AS FORECAST SOUNDINGS INDICATE A DEEPENING BOUNDARY LAYER WITH GUST POTENTIAL ABOUT 25 KNOTS. WHILE MOST AREAS WILL PROBABLY HIT THE WIND CRITERIA TODAY, THE LIMITING FACTOR WILL BE THE RELATIVE HUMIDITY VALUES. THE DEW POINTS WILL GENERALLY BE IN THE 40S TODAY, HOWEVER THE AIR TEMPERATURES WILL BE MUCH COOLER COMPARED TO YESTERDAY. THIS WILL TEND TO KEEP THE RELATIVE HUMIDITY VALUES UP. DESPITE THIS, THERE WILL STILL BE AN ENHANCED FIRE DANGER TODAY. SINCE ALL THE CRITERIA LOOKS NOT TO BE MET, WE WILL HOLD OFF ON ANY RED FLAG WARNINGS AND HIGHLIGHT THIS ENHANCED DANGER FOR MOST AREAS IN THE HAZARDOUS WEATHER OUTLOOK AND THE FIRE WEATHER FORECAST. A SPECIAL WEATHER STATEMENT /SPS/ MAY BE ISSUED LATER TO HIGHLIGHT THE ENHANCED RISK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...GORSE/O`HARA AVIATION...IOVINO MARINE...IOVINO FIRE WEATHER...GORSE [top] 000 FXUS61 KPBZ 090936 AAA AFDPBZ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 535 AM EDT THU SEP 9 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY. THE NEXT CHANCE FOR WIDESPREAD RAIN WILL ARRIVE LATE SATURDAY AND SATURDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATING TO MOVE CLOUDS FURTHER SOUTH, AS PER CURRENT SAT PICS. WILL SHIFT THE TIGHT CUTOFF OF THE CLOUD COVER FURTHER TO THE SOUTH FOR THE MORNING HOURS. THIS REMAINS TO BE THE DIFFICULT PORTION OF TODAY`S FORECAST AND WILL NEED TO MONITORED. LOCATIONS ACROSS THE FAR NORTH COULD SEE A BRIEF SHOWER OR SPRINKLE THIS AFTERNOON, AS THE MID LEVEL FLOW MOVES RIGHT ACROSS THE LAKES AND ANOTHER SW WILL MOVE SOUTHEASTWARD ON THE BACK END OF THE TROUGH. TEMPERATURES WILL BE BELOW NORMAL TODAY. AND POSSIBLY MUCH BELOW, GREATER THAN 10 DEGREES, IN THOSE LOCATIONS WHICH HOLD ONTO THE CLOUD COVER. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE SHORTWAVE WILL SLOWLY PIVOT ON THE BACKSIDE OF UPPER LOW TONIGHT PUSHING MORE CLOUDS SOUTHWARD. AGAIN SOME DIFFERENCES IN MODEL SOLUTIONS HERE AS TROUGH RETROGRADES A BIT TONIGHT AND EARLY FRIDAY. THIS WILL KEEP CLOUD COVER IN FOR A PORTION OF THE MORNING HOURS FRIDAY. PIN POINTING EXACT LOCATION OF THE CLOUD DECK IS DIFFICULT AT THIS TIME. UPPER LOW EXITS FRIDAY NIGHT WITH RIDGE IN CONTROL THROUGH AT LEAST MID DAY SATURDAY. FRONTAL BOUNDARY WILL MOVE TOWARD THE REGION SATURDAY AFTERNOON. AT THIS POINT, LOW CONFIDENCE IN TIMING AND STRENGTH OF FRONT AS IT WILL BE RUNNING INTO EASTERN RIDGE AND WILL BE AIDED BY THE MOISTURE REMNANTS OF HERMINE. LITTLE CONSENSUS AT THIS TIME IN MODEL DATA, SO WILL TRY TO FIND A COMMON GROUND AND BRING THE CHANCE FOR SHOWERS IN SATURDAY AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... STRATOCUMULUS BKN/OVC WILL PREVAIL NORTH OF PIT FOR THE NEXT 24 HOURS...WITH PERIODS OF BROKEN FOR BVI/PIT/AGC/LBE AS WELL. FOR FKL/DUJ...PATCHY MVFR IS POSSIBLE THIS MORNING...OTHERWISE LOW END VFR WILL PREVAIL THROUGH THIS AFTN...LOWERING TO MVFR TNGT. PORTS FROM PIT SOUTH WILL HAVE SCT/BKN VFR...WITH ZZV REMAINING MOSTLY CLEAR. N/NW WINDS 3-6 KT TNGT WILL INCREASE TO 8-12 KT THIS AFTN WITH AN OCCASIONAL GUST TO 20 KT. HIGH PRESSURE WILL BUILD ACROSS THE AREA BY FRIDAY...WITH ALL PORTS BECOMING VFR. THE HIGH WILL EXIT SATURDAY...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. VFR CONDITIONS ARE EXPECTED TO RETURN ON MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KLWX 090920 AAA AFDLWX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 520 AM EDT THU SEP 9 2010 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL PERSIST ACROSS THE MID ATLANTIC THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY...WITH HIGH PRESSURE RETURNING MONDAY. A SECOND COLD FRONT IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /TODAY/... UPDATE... TOOK DOWN THE SCA FOR THE NEXT SEVERAL HRS - UNTIL MID MORNING. PREV DISC... A WAVE OF VERY DRY AIR CARRIED BY GUSTY WINDS ALLOWED TEMPS TO SHARPLY RISE YESTERDAY AFTN - INTO THE M/U90S ACROSS MUCH OF THE VA/MD PIEDMONT. SFC DEWPOINTS HAVE RECOVERED BACK INTO THE U40S... WHICH IS ABOUT WHERE THEY WILL STAY THROUGH THE NEXT 24 HRS - FLUCTUATING ONLY A FEW DEGREES DURING THE PERIOD. THE STRONGER SFC WINDS HAVE ALSO SUBSIDED OVER LAND...GENERALLY DROPPING TO JUST A FEW MPH ACROSS THE REGION AND HELPING TO QUICKLY DROP TEMPS ABOUT 30 DEGREES IN SINCE LAST EVE...W/ STILL A FEW MORE DEGREES TO GO BEFORE REACHING THE OVERNIGHT LOW. THE SLOW EXIT OF THE UPPER LOW DRIFTING ACROSS THE MAINE/NEW BRUNSWICK BORDER TODAY WILL MAKE FOR ANOTHER DRY AND BREEZY DAY ACROSS THE REGION. HOWEVER...MAX TEMPS TODAY WILL BE 10-15 DEGREES LESS THAN ON WED - A SHARP CONTRAST TO THE YESTERDAY/S REMINDER THAT SUMMER HASN/T QUITE LEFT. AN UPPER LEVEL VORT MAX WILL BE STATIONED JUST TO THE NORTH AND EAST OF THE CWA - WHICH WILL KEEP THE DRIER AND BREEZIER CONDITIONS JUST TO THE NE OF THE AREA. BEHIND THE DRY COLD FRONT THAT PUSHED THROUGH THE REGION ON WED IS A CANADIAN AIRMASS THAT WILL CONTINUE TO USHER IN MUCH COOLER AIR WE/VE SEEN THE PAST COUPLE OF DAYS. FIRE WX CONCERNS IN THE SECTION BELOW. && .SHORT TERM /TONIGHT/... IN SIMILAR FASHION - THU WILL BE A BIT COOLER AND LESS WINDY THAN WED...THU NIGHT WILL BE A BIT COOLER AND LESS WINDY THAN WED NIGHT. THIS BECAUSE THE UPPER LOW WILL BE THAT MUCH FURTHER AWAY FROM THE MID ATLC...STILL SLOWLY EXITING TO THE NORTH AS CANADIAN HIGH PRESSURE SLOWLY GETS DRAWN DOWN TOWARD THE AREA. THE LAST WAVE OF UPPER ENERGY FROM THIS LOW PRESSURE SYSTEM WILL COME MIDDAY FRI...W/ ANOTHER REGIME CHANGE QUICKLY ON ITS WAY FROM THE UPPER MIDWEST. UNTIL THEN...MORE DRY NWLY WINDS AND COOLER CONDITIONS INTO FRI. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE STILL IN PLACE AT THE SURFACE ON FRIDAY. SPRAWLING UPPER LOW AND LONGWAVE TROUGH JUST OFF THE EAST COAST WILL BEGIN SHIFTING FURTHER EAST LATER FRIDAY AS MID LEVEL RIDGING BRIEFLY BUILDS ON SATURDAY. HIGH PRESSURE RIDGE MOVES OFFSHORE ON SATURDAY...AS A WARM FRONT MOVES NORTH ACROSS THE MID ATLANTIC AND A COLD FRONT MOVES EAST ACROSS THE OHIO VALLEY. THE FRONT SHOULD MOVE THROUGH THE CWFA DURING THE DAY ON SUNDAY...BRINGING A CHANCE OF MUCH NEEDED PRECIPITATION. DIDN`T MAKE ANY CHANGES TO THE POPS FOR NOW...BUT MAY HAVE TO EVENTUALLY INCREASE THEM AS THE TIMING AND STRENGTH OF THE FRONT BECOME CLEARER. HIGH PRESSURE BUILDS BRIEFLY ON MONDAY...WITH ANOTHER COLD FRONT EXPECTED FOR THE MIDDLE OF THE WEEK. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... WINDS HAVE FINALLY SUBSIDED ACROSS THE REGION /OUTSIDE OF AREAS CLOSER TO THE CHESAPEAKE BAY/. THO MOST SITES ARE SHOWING WINDS NEAR 5KT OR LESS...A FAIRLY TURBULENT UPPER LOW STILL EXISTS TO THE NE WHICH WILL CONTINUE TO STREAM WAVES OF LOW LEVEL WINDS ACROSS THE MID ATLC /10-15KT/ AS THEY SLIDE ACROSS THE REGION OVERNIGHT. THESE CONDITIONS WILL ONLY INCREASE AFTER SUNRISE - W/ PEAK GUSTS BACK INTO THE 20-25KT RANGE THOUGH MORE INTERMITTENT THAN ON WED. MODELS SHOWING A SCT 6-8KFT DECK SCATTERED ABOUT THE AREA DURING THE DAYTIME HRS...SO SOLID VFR CONDITIONS WILL PERSIST THRU THE CURRENT TAF CYCLE. BREEZY NW WINDS WILL CONTINUE THROUGH FRIDAY AFTERNOON. SUB VFR CIGS/VSBYS POSSIBLE SATURDAY INTO SUNDAY AS A COLD FRONT CROSS THE AREA...ACCOMPANIED BY SCT CONVECTION. NW WINDS EXPECTED BEHIND THE FRONT. && .MARINE... SOLID SCA CONDITIONS WILL PERSIST INTO TODAY/TONIGHT AND FRI. INTERMITTENT PERIODS OF LOWER WIND VALUES /5-10KT/ WILL OCCUR DURING THIS TIME PERIOD...BUT THE WATERS WILL BE IN AT LEAST MARGINAL SCA WELL INTO FRI. THE UPPER LOW RESPONSIBLE FOR PUSHING THESE BREEZY CONDITIONS ACROSS THE REGION IS VERY SLOWLY DRIFTING OVER NRN NEW ENGLAND AND WILL FINALLY EXIT OFF THE COAST BY EARLY SAT. NW WINDS WILL CONTINUE ACROSS THE WATERS THROUGH FRIDAY AFTERNOON...AND TURN MORE NORTHERLY FRIDAY NIGHT. SMALL CRAFT CONDITIONS WILL CONTINUE THROUGH FRIDAY AFTERNOON...BUT DO EXPECT GUSTINESS TO DIMINISH AS AN UPPER LOW PUSHES EAST LATE FRIDAY INTO EARLY SATURDAY. A COLD FRONT WILL MOVE ACROSS THE WATERS ON SUNDAY...FOLLOWED BY HIGH PRESSURE ON MONDAY. && .FIRE WEATHER... FIRE WX STILL A CONCERN AFTER THE ROUGH CONDITIONS ON WED W/ DEWPOINTS IN THE 30S AND WIND GUSTS IN THE 25-35MPH RANGE...AND NOT TO MENTION HIGH TEMPS WELL INTO THE 90S. CONDITIONS THOUGH WILL BE A BIT LESS SEVERE FOR THU...W/ REL HUMIDITY VALUES IN THE 30S /AS OPPOSED TO THE TEENS/ - WIND GUSTS 20-25MPH AND HIGHS BARELY REACHING 80 BY MID AFTN. THESE CONDITIONS POINT MORE TO AN ENHANCED THREAT OF FIRE DANGER FOR TODAY...AS OPPOSED TO THE RED FLAG CONDITIONS OF YESTERDAY...THOUGH THE AREA REMAINS ABNORMALLY DRY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT FRIDAY FOR ANZ530>534-537>543. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING FOR ANZ535-536. && $$ UPDATE...GMS PREV DISCUSSION...GMS/LISTEMAA 000 FXUS61 KAKQ 090854 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 454 AM EDT THU SEP 9 2010 .SYNOPSIS... A DRY COLD FRONT WILL DROP SOUTH OF THE CAROLINA COAST TODAY...AS HIGH PRESSURE BUILDS INTO THE MID ATLANTIC REGION FROM THE NORTH THROUGH FRIDAY. THE HIGH WILL SLIDE OFF THE COAST ON SATURDAY... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... COLD FRONT CONTINUES TO MAKE STEADY SOUTHWARD PROGRESS...NOW PUSHING S OF CAPE HATTERAS. MEANWHILE...A SECONDARY SFC FRONT (MORE OF A DWPT BNDRY) HAS NOW PUSHED INTO SOUTHSIDE VA. THERE CONTINUES TO BE QUITE A DEWPOINT GRADIENT N-S ACROSS THE FCST AREA... FROM THE UPR 40S N TO THE MID 60S S. TODAY...DEEP-LAYER RIDGING WILL CONTINUE TO BUILD ACROSS THE MID ATLC REGION...IN BETWEEN THE UPR LOW OVER NRN NEW ENGLAND AND RIDGE AXIS OVER THE CENTRAL CONUS. THIS WILL LEAD TO CONTINUED DRYING CONDITIONS AND MSTLY SUNNY SKIES ACROSS THE REGION...THOUGH GIVEN THE DEEP NW FLOW AND EARLY-SEASON INSTBY OVER THE WRN GREAT LAKES...CANNOT RULE OUT SCT TO OCNLY BKN LAKE-ORIGINATED CU ADVECTING ALL THE WAY INTO THE LWR MD ERN SHORE. IN THIS REGION... EXPECT MORE OF A FLUCTUATION WITH THE CLOUD COVER DURING THE AFTN (MSTLY-PTLY SUNNY)...WHICH WOULD HAVE AN IMPACT ON TEMPS. FOR NOW...HAVE STUCK WITH HIGHS IN THE UPR 70S OVER THE LWR MD ERN SHORE...HOWEVER THE LATEST GUIDANCE (INCLUDING THE MOST RECENT LAMP OR LAV GUIDANCE) WOULD SUGGEST MID 70S TOPS. WILL CONTINUE TO KEEP AN EYE ON TRENDS AND MAKE FURTHER ADJUSTMENTS TO THE FCST AS NECESSARY. ELSEWHERE...LOCAL 1000-850 MB THICKNESS GUIDANCE SUPPORTS HIGHS 80-85F...HIGHEST S/W OF A FVX-PTB-FKN LINE. OF GREATER CONCERN WILL AGAIN BE THE INCREASED FIRE DANGER. WILL CONTINUE WITH THE SPS OVER INLAND AREAS (W OF CHES BAY)...AS AGAIN EXPECT MIN RH`S IN THE 20-25 PCT RANGE. SUSTAINED WINDS WILL BE TOO LIGHT TO JUSTIFY RED FLAG WARNINGS (AROUND 10-12 MPH)...HOWEVER AGAIN EXPECT A FAIRLY GOOD GUST FACTOR TODAY WITH THE DEEPENING MIXED LAYER (GUSTS 20-25 MPH). OVER THE LWR ERN SHORE...WINDS WILL BE STRONGER (MORE LIKE 15-20 MPH WITH GUSTS TO 30)...HOWEVER AT THE SAME TIME RH`S WILL BE HIGHER IN THIS REGION (30-40%) GIVEN MORE STRATO-CU CLOUD COVER AND WITH THE SLIGHT INCREASE IN LLVL MSTR AS LLVL WINDS CROSS CHES BAY. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... FEW CHANGES MADE TO THE PREVIOUS FCSTS. AS THE SFC HIGH CONTINUES TO BUILD INTO THE MID ATLC REGION TONIGHT...SFC WINDS MAY HAVE A TOUGH TIME DECOUPLING OVER MUCH OF THE FCST AREA (ESPECIALLY DOWNWIND OF CHES BAY). THEREFORE...EXPECT THE DEGREE OF RADIATIONAL COOLING TO BE LIMITED SOMEWHAT TONIGHT...THUS OPTED TO NOT UNDERCUT MOS BLEND TEMPS FOR TONIGHT. ANOTHER NICE DAY ON FRI...WITH THE LLVL THICKNESS PROFILES GIVEN MOSTLY SUNNY CONDITIONS SUPPORTING HIGHS IN THE MID 70S LWR MD ERN SHORE AND FROM THE UPR 70S TO LWR 80S FROM NE-SW ACROSS THE REST OF THE REGION. SURFACE HIGH PRESSURE WILL LIKELY REMAIN OVER THE REGION FOR DRY WEATHER AGAIN ON SATURDAY. HOWEVER...THE NEXT SYSTEM WILL LIKELY BRING SOME CLOUDS TO THE AREA LATE IN THE DAY. MODELS KEEP PRECIP WEST OF OUR AREA THROUGH SATURDAY AFTERNOON...SO WILL CONTINUE WITH A DRY FORECAST FOR NOW. HIGH TEMPS WILL BE IN THE LOW/MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT APPROACHES FROM THE WEST SATURDAY NIGHT AND SUNDAY. CLOUDS WILL INCREASE AHEAD OF THE FRONT WITH A CHANCE FOR SHOWERS SUNDAY ALONG WITH THE POSSIBILITY OF THUNDER DURING THE AFTERNOON AND EVENING. CLOUD COVER SHOULD HOLD MAXIMUM TEMPERATURES IN THE LOW TO MID 80S. THE COLD FRONT CLEARS THE COAST LATER SUNDAY NIGHT WITH DRY AND MILD CONDITIONS PREVAILING EARLY NEXT WEEK WITH HIGH TEMPERATURES REMAINING THE LOW TO MID 80S...AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S. ANOTHER COLD FRONT APPROACHES THE MIDDLE OF NEXT WEEK WITH LITTLE INDICATION OF ANY MOISTURE. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... HI PRES WILL BLD INTO AND OVR THE REGION FOR TDY INTO SAT. THIS WILL RESULT IN VFR CONDITIONS CONTINUING OVR THE AREA. FOR TDY INTO FRI MORNG...EXPECT NW OR N WNDS 10 TO 20 MPH THIS AFTN WITH STRNGEST WNDS AT SBY. LWR CIGS/VSBYS POSSIBLE LATE SAT NGT THRU SUN...WHEN NEXT COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... WILL MAINTAIN SCA FOR THE CHES BAY AND NRN TWO CSTL ZNS THRU 7 AM THIS MORNG...DUE TO GUSTY NW OR N WNDS BEHIND THE FRNT. THEN...THE MIXING PROFILE BECOMES MORE STABLE OVR THE WATER DURING TDY. ANOTHER NW OR NW WND SURGE ARRIVES TNGT. IT IS NOT QUITE AS STRONG...AND WNDS SHUD REMAIN JUST BELOW SCA CONDITIONS. HI PRES WILL BLD OVR THE AREA FRI INTO SAT...WITH ANOTHER COLD FRNT APPROACHING AND MOVNG THRU SUN. && .FIRE WEATHER... AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER TODAY COMPARED TO WED... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS EXPECTED...WILL AGAIN HIGHLIGHT THE THREAT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON IN A SPECIAL WEATHER STATEMENT. THIS STATEMENT WILL INCLUDE ALL OF OUR COUNTIES IN VA EXCEPT FAR SE VA AND THE LOWER EASTERN SHORE. IT WILL ALSO INCLUDE THE LOWER MD EASTERN SHORE. AN ADDITIONAL STATEMENT MAY BE NECESSARY FOR FRIDAY AS CONDITIONS ARE EXPECTED TO BE SIMILAR TO THURSDAY. && .CLIMATE... WITH TODAY`S HIGH OF 90 F AT RICHMOND...THERE HAVE NOW BEEN 71 DAYS THIS YEAR WITH A HIGH OF 90 F OR HIGHER. THIS IS THE MOST ON RECORD AT RIC...SURPASSING THE 70 DAYS OF 90+ BACK IN 1977. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ630>632-650-652. && $$ SYNOPSIS...BKH NEAR TERM...BKH SHORT TERM...BKH/JDM LONG TERM...AJZ AVIATION...TMG MARINE...TMG FIRE WEATHER...JDM CLIMATE...LKB 000 FXUS61 KPBZ 090844 AAA AFDPBZ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 444 AM EDT THU SEP 9 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY. THE NEXT CHANCE FOR WIDESPREAD RAIN WILL ARRIVE LATE SATURDAY AND SATURDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATING TO MOVE CLOUDS FURTHER SOUTH, AS PER CURRENT SAT PICS. WILL SHIFT THE TIGHT CUTOFF OF THE CLOUD COVER FURTHER TO THE SOUTH FOR THE MORNING HOURS. THIS REMAINS TO BE THE DIFFICULT PORTION OF TODAY`S FORECAST AND WILL NEED TO MONITORED. LOCATIONS ACROSS THE FAR NORTH COULD SEE A BRIEF SHOWER OR SPRINKLE THIS AFTERNOON, AS THE MID LEVEL FLOW MOVES RIGHT ACROSS THE LAKES AND ANOTHER SW WILL MOVE SOUTHEASTWARD ON THE BACK END OF THE TROUGH. TEMPERATURES WILL BE BELOW NORMAL TODAY. AND POSSIBLY MUCH BELOW, GREATER THAN 10 DEGREES, IN THOSE LOCATIONS WHICH HOLD ONTO THE CLOUD COVER. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE SHORTWAVE WILL SLOWLY PIVOT ON THE BACKSIDE OF UPPER LOW TONIGHT PUSHING MORE CLOUDS SOUTHWARD. AGAIN SOME DIFFERENCES IN MODEL SOLUTIONS HERE AS TROUGH RETROGRADES A BIT TONIGHT AND EARLY FRIDAY. THIS WILL KEEP CLOUD COVER IN FOR A PORTION OF THE MORNING HOURS FRIDAY. PIN POINTING EXACT LOCATION OF THE CLOUD DECK IS DIFFICULT AT THIS TIME. UPPER LOW EXITS FRIDAY NIGHT WITH RIDGE IN CONTROL THROUGH AT LEAST MID DAY SATURDAY. FRONTAL BOUNDARY WILL MOVE TOWARD THE REGION SATURDAY AFTERNOON. AT THIS POINT, LOW CONFIDENCE IN TIMING AND STRENGTH OF FRONT AS IT WILL BE RUNNING INTO EASTERN RIDGE AND WILL BE AIDED BY THE MOISTURE REMNANTS OF HERMINE. LITTLE CONSENSUS AT THIS TIME IN MODEL DATA, SO WILL TRY TO FIND A COMMON GROUND AND BRING THE CHANCE FOR SHOWERS IN SATURDAY AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... STRATOCUMULUS BKN/OVC WILL PREVAIL NORTH OF PIT FOR THE NEXT 24 HOURS...WITH PERIODS OF BROKEN FOR BVI/PIT/AGC/LBE AS WELL. FOR FKL/DUJ...PATCHY MVFR IS POSSIBLE THIS MORNING...OTHERWISE LOW END VFR WILL PREVAIL THROUGH THIS AFTN...LOWERING TO MVFR TNGT. PIT/LBE/BVI/AGC WILL REMAIN VFR...WITH PORTS TO THE SOUTH REMAINING MOSTLY CLEAR. N/NW WINDS 3-6 KT TNGT WILL INCREASE TO 8-12 KT THIS AFTN WITH AN OCCASIONAL GUST TO 20 KT. HIGH PRESSURE WILL BUILD ACROSS THE AREA BY FRIDAY...WITH ALL PORTS BECOMING VFR. THE HIGH WILL EXIT SATURDAY...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. VFR CONDITIONS ARE EXPECTED TO RETURN ON MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPBZ 090823 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 423 AM EDT THU SEP 9 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY. THE NEXT CHANCE FOR WIDESPREAD RAIN WILL ARRIVE LATE SATURDAY AND SATURDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... AREA OF STRATOCU IS COVERING LOCATIONS FROM PIT NORTH. SOME DISAGREEMENT IN MODELS TODAY ON HOW LONG THESE CLOUDS WILL HANG AROUND AND HOW MUCH FURTHER SOUTH, IF AT ALL, THEY WILL MOVE. WILL KEEP MORE CLOUDS IN FOR LOCATIONS FROM PIT NORTH INTO THE AFTERNOON, WITH MS CONDITIONS TO THE SOUTH. THE TIGHT CUTOFF OF THE CLOUD COVER SHOULD LAST THROUGHOUT THE DAY. THIS WILL BE THE DIFFICULT PORTION OF TODAY`S FORECAST AND WILL NEED TO MONITORED. LOCATIONS ACROSS THE FAR NORTH COULD SEE A BRIEF SHOWER OR SPRINKLE THIS AFTERNOON, AS THE MID LEVEL FLOW MOVES RIGHT ACROSS THE LAKES AND ANOTHER SW WILL MOVE SOUTHEASTWARD ON THE BACK END OF THE TROUGH. TEMPERATURES WILL BE BELOW NORMAL TODAY. AND POSSIBLY MUCH BELOW, GREATER THAN 10 DEGREES, IN THOSE LOCATIONS WHICH HOLD ONTO THE CLOUD COVER. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... THE SHORTWAVE WILL SLOWLY PIVOT ON THE BACKSIDE OF UPPER LOW TONIGHT PUSHING MORE CLOUDS SOUTHWARD. AGAIN SOME DIFFERENCES IN MODEL SOLUTIONS HERE AS TROUGH RETROGRADES A BIT TONIGHT AND EARLY FRIDAY. THIS WILL KEEP CLOUD COVER IN FOR A PORTION OF THE MORNING HOURS FRIDAY. PIN POINTING EXACT LOCATION OF THE CLOUD DECK IS DIFFICULT AT THIS TIME. UPPER LOW EXITS FRIDAY NIGHT WITH RIDGE IN CONTROL THROUGH AT LEAST MID DAY SATURDAY. FRONTAL BOUNDARY WILL MOVE TOWARD THE REGION SATURDAY AFTERNOON. AT THIS POINT, LOW CONFIDENCE IN TIMING AND STRENGTH OF FRONT AS IT WILL BE RUNNING INTO EASTERN RIDGE AND WILL BE AIDED BY THE MOISTURE REMNANTS OF HERMINE. LITTLE CONSENSUS AT THIS TIME IN MODEL DATA, SO WILL TRY TO FIND A COMMON GROUND AND BRING THE CHANCE FOR SHOWERS IN SATURDAY AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... STRATOCUMULUS BKN/OVC WILL PREVAIL NORTH OF PIT FOR THE NEXT 24 HOURS...WITH PERIODS OF BROKEN FOR BVI/PIT/AGC/LBE AS WELL. FOR FKL/DUJ...PATCHY MVFR IS POSSIBLE THIS MORNING...OTHERWISE LOW END VFR WILL PREVAIL THROUGH THIS AFTN...LOWERING TO MVFR TNGT. PIT/LBE/BVI/AGC WILL REMAIN VFR...WITH PORTS TO THE SOUTH REMAINING MOSTLY CLEAR. N/NW WINDS 3-6 KT TNGT WILL INCREASE TO 8-12 KT THIS AFTN WITH AN OCCASIONAL GUST TO 20 KT. HIGH PRESSURE WILL BUILD ACROSS THE AREA BY FRIDAY...WITH ALL PORTS BECOMING VFR. THE HIGH WILL EXIT SATURDAY...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. VFR CONDITIONS ARE EXPECTED TO RETURN ON MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 090741 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 341 AM EDT THU SEP 9 2010 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL REMAIN NEAR NORTHERN NEW ENGLAND TODAY, THEN GRADUALLY SHIFT EASTWARD TONIGHT AND FRIDAY. MEANWHILE, HIGH PRESSURE OVER THE MIDWEST WILL SLOWLY SHIFT EASTWARD THROUGH FRIDAY NIGHT, EVENTUALLY SETTLING OVER OUR AREA SATURDAY. THIS HIGH PRESSURE SYSTEM WILL THEN MOVE OFFSHORE LATE SATURDAY. A COLD FRONT WILL CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT SLIDES THROUGH LATE TUESDAY, THEN HIGH PRESSURE BEGINS TO BUILD TOWARD OUR AREA WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A 06Z SURFACE ANALYSIS PLACED A COLD FRONT OFF THE COAST OF NEW ENGLAND AND THE MID ATLANTIC THEN BACK DOWN INTO THE GULF COAST STATES. HIGH PRESSURE WAS SITUATED FROM THE WESTERN GREAT LAKES TO CENTRAL CANADA. AN UPPER AIR ANALYSIS PLACED A CLOSED LOW OVER NORTHERN NEW ENGLAND WITH SEVERAL SHORT WAVES ROTATING AROUND IT. A 300 MB JET WAS LOCATED FROM THE UPPER GREAT LAKES TO THE MID ATLANTIC REGION. OUR WEATHER TODAY WILL BE CONTROLLED BY A STRONG CLOSED LOW ANCHORED NEAR NORTHERN NEW ENGLAND WITH CYCLONIC FLOW OCCURRING ACROSS THE MID ATLANTIC AND NORTHEAST. A NORTHWESTERLY FLOW OF COOLER AIR WILL COMBINE WITH A TIGHTENED PRESSURE GRADIENT TO PRODUCE BREEZY TO WINDY CONDITIONS. THE WINDS HAVE DIMINISHED HOWEVER AS DAYTIME HEATING OCCURS, THE BOUNDARY LAYER MIXING WILL DEEPEN WITH TIME ALLOWING FOR BETTER VERTICAL MIXING. IF WE MIX TO THE FULL POTENTIAL, WE WOULD BE ABLE TO TAP SOME 25 KNOTS OF WIND. THEREFORE, WE WILL CONTINUE TO CARRY INCREASED WINDS THROUGH THE DAY, BEFORE SOME DROPPING OFF IS EXPECTED TOWARD SUNSET AS THE LOSS OF DAYTIME HEATING OCCURS. THE CYCLONIC FLOW COUPLED WITH CAA AND ADDED MOISTURE FROM THE GREAT LAKES CONTINUES TO GENERATE A WEALTH OF STRATOCUMULUS TO OUR NORTHWEST. AN AREA OF CHANNELIZED VORTICITY IS LIKELY ENHANCING THIS CLOUD COVER, AND THIS VORTICITY IS FORECAST TO BE MAINTAINED THROUGH TODAY AND EVEN SETTLE SOUTHWARD SOME. THIS WILL TEND TO KEEP CLOUDS MORE CONCENTRATED THE FARTHER NORTH ONE GOES. THE FORECAST CHALLENGE TODAY IS HOW MUCH IN THE WAY OF STRATOCUMULUS CAN EITHER BE PULLED INTO OUR AREA OR FORM. THE FORECAST SOUNDINGS HAVE A HINT OF A LITTLE INSTABILITY DEVELOPING THIS AFTERNOON AS BOUNDARY LAYER MIXING IS MAXIMIZED. THIS SHALLOW RIBBON OF INSTABILITY IS WHERE THE CLOUDS WOULD BE AND THIS POINTS MAINLY ACROSS OUR NORTHERN ZONES. FARTHER SOUTH, THE CHANNELIZED VORTICITY IS FORECAST TO ARRIVE MUCH LATER IN THE DAY AND THE AIRMASS IS ACTUALLY DRIER WITH MORE OF A CAP. THE FLY IN THE OINTMENT WOULD BE IF CLOUDS DEVELOP SINCE THE CONVECTIVE TEMPERATURES SHOULD BE REACHED AND THE MOISTURE BECOMES TRAPPED UNDER THE INVERSION. WE ARE LEANING TOWARD THIS AND FOR NOW WE INCREASED THE SKY COVER SOME BUT STILL MAINTAINED MORE COVERAGE UP NORTH COMPARED TO DOWN SOUTH. THE NORTHWESTERLY FLOW IS GENERATING LAKE EFFECT RAIN SHOWERS ACROSS WESTERN AND CENTRAL NEW YORK. THE TRAJECTORY WOULD FAVOR THIS BEING PUSHED TOWARD NORTHEASTERN PENNSYLVANIA, AND THIS COULD BE HELPED TO SOME EXTENT BY THE CHANNELIZED VORTICITY. SINCE THIS ACTIVITY WOULD BE MOVING FARTHER AWAY FROM ITS MAIN MOISTURE SOURCE /LAKES ONTARIO AND ERIE/, PERHAPS A LIGHT SHOWER OR SOME SPRINKLES GET TO THE SOUTHERN POCONOS AND FAR NORTHWESTERN NEW JERSEY. AM NOT REAL CONFIDENT IF MEASURABLE PRECIPITATION OCCURS, THEREFORE WILL GO WITH POPS BELOW 15 PERCENT AND ADD A CHC OF SPRINKLES FOR NOW. AS FOR TEMPERATURES, WE GENERALLY SIDED WITH A BLEND OF THE GFS/NAM MOS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE LARGE CLOSED LOW OVER NEW ENGLAND IS FORECAST TO SLIDE SOUTHWARD TONIGHT, PUSHING THE CHANNELIZED VORTICITY THROUGH THE NORTHERN MID ATLANTIC REGION. THE GFS ACTUALLY HAS A MORE FOCUSED SHORT WAVE ROTATING AROUND THE CLOSED LOW, WHILE SOME OF THE OTHER GUIDANCE IS MORE CHANNELIZED. WE ARE NOT ANTICIPATING ANY PRECIPITATION WITH THIS, HOWEVER IT MAY IMPACT THE CLOUD COVER FORECAST. THERE SHOULD BE A FAIR AMOUNT OF STRATOCUMULUS AROUND IN THE EVENING WITH MORE UP NORTH COMPARED TO THE DELMARVA. WITH THE LOSS OF DAYTIME HEATING, THE STRATOCUMULUS SHOULD TEND TO FLATTEN OUT AND DISSIPATE FROM SOUTH TO NORTH. THE NORTHERN ZONES SHOULD TEND TO HOLD ONTO MORE IN THE WAY CLOUDS LONGER GIVEN THE CLOSER PROXIMITY OF THE CLOSED LOW AND THE NORTHWESTERLY FLOW OFF THE EASTERN GREAT LAKES. WHILE THE PRESSURE GRADIENT IS FORECAST TO REMAIN TIGHTENED TONIGHT ALONG WITH SOME CAA, WE SHOULD BE ABLE TO DECOUPLE MORE QUICKLY AS THE LOW-LEVEL FLOW IS WEAKER AND THE BOUNDARY LAYER BECOMES MORE SHALLOW AND COOLS. FOR FRIDAY, THE THERMAL ADVECTION BECOMES MORE NEUTRAL THEREFORE WHILE AT LEAST SOME CLOUDS WILL DEVELOP THEY SHOULD TEND TO FLATTEN OUT QUICKLY THROUGH THE AFTERNOON AND EARLY EVENING AS SOME ADDITIONAL DRYING IS NOTED IN THE FORECAST SOUNDINGS MAINLY ABOVE 6,000 FEET. THE CYCLONIC FLOW ALOFT CONTINUES FRIDAY, ALTHOUGH THE LOW-LEVEL FLOW APPEARS TO BECOME A BIT MORE ANTICYCLONIC. THIS WILL ALLOW THE PRESSURE GRADIENT TO RELAX FRIDAY AND FRIDAY NIGHT, ALTHOUGH THE FORECAST SOUNDINGS DO INDICATE ENOUGH VERTICAL MIXING OCCURS YET AGAIN FRIDAY FOR POTENTIALLY BREEZY CONDITIONS. MUCH BETTER DECOUPLING THEN TAKES PLACE FRIDAY NIGHT AS A SURFACE HIGH BEGINS TO SETTLE IN AND THE CLOSED SLOW SHIFTS EAST. FOR SATURDAY, HIGH PRESSURE FROM SOUTHEASTERN CANADA SETTLES OVER THE AREA AS MIDLEVEL RIDGING ARRIVES FROM THE WEST. THE PATTERN LOOKS FAIRLY PROGRESSIVE THEREFORE THE SURFACE HIGH WILL BEGIN SHIFTING OFFSHORE TOWARD EVENING. LIGHTER WINDS WITH NO SIGNIFICANT WEATHER EXPECTED, ALTHOUGH EITHER A SEA BREEZE DEVELOPS OR MERGES WITH THE LOW-LEVEL FLOW EVENTUALLY SHIFTING FROM A SOUTHERLY DIRECTION. AS FOR TEMPERATURES, WE MOSTLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE GFS AND NAM MOS WITH JUST SOME MINOR ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE CWA ARRIVES DURING THE START OF THIS TIME FRAME. MOISTURE FROM THE REMNANTS OF TROPICAL STORM HERMINE MAY GET CAUGHT UP WITH A COLD FRONT AND UPPER-LEVEL TROUGH ADVANCING FROM THE NORTHERN/CENTRAL PLAINS. AS THE UPPER-LEVEL TROUGH INITIALLY AMPLIFIES ACROSS THE PLAINS, ANY TRAPPED MOISTURE SHOULD BE PULLED NORTHWARD. DOWNSTREAM THOUGH, RIDGING WILL BE ENHANCED ALTHOUGH GIVEN THE AMPLIFICATION OF THE PATTERN EVERYTHING SHOULD BE PROGRESSIVE. DESPITE THE LARGE TROUGH FORECAST TO BE EXITING THE EAST COAST, THE STRENGTH OF THE INCOMING TROUGH SHOULD BE ENOUGH TO PUSH THE RIDGE EASTWARD WITH TIME. THERE ARE SOME TIMING DIFFERENCES REGARDING THE ARRIVAL OF THE POTENTIAL SHOWERS/STORMS, AS THE NAM/WRF IS BELIEVED TO BE TO SLOW GIVEN THE PATTERN WHILE THE GFS/ECMWF ARE PROBABLY TO FAST. THE FASTER MODEL SOLUTIONS APPEAR TO HAVE THE STRONGEST LOW TO MID LEVEL THETA-E ADVECTION LAGGING BEHIND THE QPF. THEREFORE, MADE SOME TIMING ADJUSTMENTS TO THE POPS SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE POPS WILL REMAIN IN THE CHC CATEGORY FOR NOW, AND THE REGION REALLY DOES NEED THE RAIN AND THIS LOOKS LIKE OUR BEST CHC SINCE WEEKS AGO. IT WILL BE INTERESTING REGARDING HOW MUCH PRECIPITATION OCCURS WITH THIS SYSTEM AS MUCH OF THE MODEL GUIDANCE HAS THE UPPER-LEVEL TROUGH DEAMPLIFYING AS IT MOVES EASTWARD. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SURFACE HIGH PRESSURE FOLLOWS FOR MONDAY WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SOUTHEASTWARD FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SOME SHOWERS TUESDAY INTO WEDNESDAY, THEN HIGH PRESSURE NEAR THE MIDWEST BEGINS TO SLIDE EASTWARD TOWARD THE MID ATLANTIC DURING WEDNESDAY. THERE ARE NO REAL LARGE RIDGES FORECAST TO BE PERSISTENT AS THE NORTHERN STREAM LOOKS TO DOMINATE, THUS NO EXCESSIVE HEAT IS ANTICIPATED DURING THIS ENTIRE TIME FRAME. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AT 0730Z, THE SKY OVER OUR EIGHT TAF SITES WAS MOSTLY CLEAR AND THERE WERE NO VISIBILITY RESTRICTIONS. THE WIND WAS MAINLY FROM THE WEST AND NORTHWEST AT LESS THAN 10 KNOTS. LITTLE CHANGE IS EXPECTED THROUGH DAYBREAK, AROUND 1100Z. VFR CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE TAF PERIOD EVEN THOUGH A DECK OF BROKEN STRATOCUMULUS IS EXPECTED OVER OUR REGION FOR MUCH OF THE AFTERNOON INTO THE EARLY EVENING. THE CLOUD BASES SHOULD BE 5000 FEET OR GREATER. THE MAIN WEATHER IMPACT TODAY WILL BE THE WIND. A WEST NORTHWEST WIND AROUND 15 KNOTS WILL DEVELOP THIS MORNING AND IT SHOULD CONTINUE INTO THE EARLY EVENING. WIND GUSTS INTO THE 20S ARE LIKELY. AFTER SUNSET, AROUND 2300Z, WIND SPEEDS ARE FORECAST TO DIMINISH. OUTLOOK... HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER CONDITIONS FROM TONIGHT INTO SATURDAY. A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO BRING SHOWERS TO OUR REGION FROM LATE SATURDAY NIGHT INTO SUNDAY NIGHT. DRY WEATHER SHOULD RETURN FOR MONDAY. && .MARINE... A PUSH OF COOL DRY AIR OVERNIGHT RESULTED IN SOME WIND GUSTS AROUND 25 KNOTS ON OUR COASTAL WATERS. AS THE EARLY MORNING HOURS PROGRESS, THE GUSTS SHOULD DIMINISH INTO THE 20 KNOT NEIGHBORHOOD. AS A RESULT, WE WILL DISCONTINUE TO SMALL CRAFT ADVISORY. LOW PRESSURE WILL REMAIN OVER CANADA`S ATLANTIC PROVINCES AND THE ADJACENT WATERS INTO SATURDAY AS HIGH PRESSURE BUILDS INTO OUR REGION FROM THE WEST. WHILE THE WIND SHOULD REMAIN GUSTY INTO FRIDAY, IT APPEARS AS THOUGH GUSTS WILL STAY AROUND 20 KNOTS SO WE SHOULD NOT NEED TO REISSUE THE SMALL CRAFT ADVISORY. A FRONTAL BOUNDARY IS FORECAST TO APPROACH FROM THE WEST AND IT IS EXPECTED TO ARRIVE ON SUNDAY. IT DOES NOT APPEAR AS THOUGH THE PRESSURE GRADIENT IN THE VICINITY OF THE FRONT WILL PRODUCE WIND GUSTS IN EXCESS OF ABOUT 20 KNOTS. HIGH PRESSURE SHOULD FOLLOW FOR MONDAY. && .FIRE WEATHER... THE RATHER DRY CONDITIONS WILL CONTINUE AS THE FINE FUELS ARE EXCEPTIONALLY DRY. A NORTHWESTERLY WIND WILL BE GUSTY TODAY, AS FORECAST SOUNDINGS INDICATE A DEEPENING BOUNDARY LAYER WITH GUST POTENTIAL ABOUT 25 KNOTS. WHILE MOST AREAS WILL PROBABLY HIT THE WIND CRITERIA TODAY, THE LIMITING FACTOR WILL BE THE RELATIVE HUMIDITY VALUES. THE DEW POINTS WILL GENERALLY BE IN THE 40S TODAY, HOWEVER THE AIR TEMPERATURES WILL BE MUCH COOLER COMPARED TO YESTERDAY. THIS WILL TEND TO KEEP THE RELATIVE HUMIDITY VALUES UP. DESPITE THIS, THERE WILL STILL BE AN ENHANCED FIRE DANGER TODAY. SINCE ALL THE CRITERIA LOOKS NOT TO BE MET, WE WILL HOLD OFF ON ANY RED FLAG WARNINGS AND HIGHLIGHT THIS ENHANCED DANGER FOR MOST AREAS IN THE HAZARDOUS WEATHER OUTLOOK AND THE FIRE WEATHER FORECAST. A SPECIAL WEATHER STATEMENT /SPS/ MAY BE ISSUED LATER TO HIGHLIGHT THE ENHANCED RISK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...GORSE/O`HARA AVIATION...IOVINO MARINE...IOVINO FIRE WEATHER...GORSE 000 FXUS61 KLWX 090731 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 331 AM EDT THU SEP 9 2010 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL PERSIST ACROSS THE MID ATLANTIC THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY...WITH HIGH PRESSURE RETURNING MONDAY. A SECOND COLD FRONT IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /TODAY/... A WAVE OF VERY DRY AIR CARRIED BY GUSTY WINDS ALLOWED TEMPS TO SHARPLY RISE YESTERDAY AFTN - INTO THE M/U90S ACROSS MUCH OF THE VA/MD PIEDMONT. SFC DEWPOINTS HAVE RECOVERED BACK INTO THE U40S... WHICH IS ABOUT WHERE THEY WILL STAY THROUGH THE NEXT 24 HRS - FLUCTUATING ONLY A FEW DEGREES DURING THE PERIOD. THE STRONGER SFC WINDS HAVE ALSO SUBSIDED OVER LAND...GENERALLY DROPPING TO JUST A FEW MPH ACROSS THE REGION AND HELPING TO QUICKLY DROP TEMPS ABOUT 30 DEGREES IN SINCE LAST EVE...W/ STILL A FEW MORE DEGREES TO GO BEFORE REACHING THE OVERNIGHT LOW. THE SLOW EXIT OF THE UPPER LOW DRIFTING ACROSS THE MAINE/NEW BRUNSWICK BORDER TODAY WILL MAKE FOR ANOTHER DRY AND BREEZY DAY ACROSS THE REGION. HOWEVER...MAX TEMPS TODAY WILL BE 10-15 DEGREES LESS THAN ON WED - A SHARP CONTRAST TO THE YESTERDAY/S REMINDER THAT SUMMER HASN/T QUITE LEFT. AN UPPER LEVEL VORT MAX WILL BE STATIONED JUST TO THE NORTH AND EAST OF THE CWA - WHICH WILL KEEP THE DRIER AND BREEZIER CONDITIONS JUST TO THE NE OF THE AREA. BEHIND THE DRY COLD FRONT THAT PUSHED THROUGH THE REGION ON WED IS A CANADIAN AIRMASS THAT WILL CONTINUE TO USHER IN MUCH COOLER AIR WE/VE SEEN THE PAST COUPLE OF DAYS. FIRE WX CONCERNS IN THE SECTION BELOW. && .SHORT TERM /TONIGHT/... IN SIMILAR FASHION - THU WILL BE A BIT COOLER AND LESS WINDY THAN WED...THU NIGHT WILL BE A BIT COOLER AND LESS WINDY THAN WED NIGHT. THIS BECAUSE THE UPPER LOW WILL BE THAT MUCH FURTHER AWAY FROM THE MID ATLC...STILL SLOWLY EXITING TO THE NORTH AS CANADIAN HIGH PRESSURE SLOWLY GETS DRAWN DOWN TOWARD THE AREA. THE LAST WAVE OF UPPER ENERGY FROM THIS LOW PRESSURE SYSTEM WILL COME MIDDAY FRI...W/ ANOTHER REGIME CHANGE QUICKLY ON ITS WAY FROM THE UPPER MIDWEST. UNTIL THEN...MORE DRY NWLY WINDS AND COOLER CONDITIONS INTO FRI. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE STILL IN PLACE AT THE SURFACE ON FRIDAY. SPRAWLING UPPER LOW AND LONGWAVE TROUGH JUST OFF THE EAST COAST WILL BEGIN SHIFTING FURTHER EAST LATER FRIDAY AS MID LEVEL RIDGING BRIEFLY BUILDS ON SATURDAY. HIGH PRESSURE RIDGE MOVES OFFSHORE ON SATURDAY...AS A WARM FRONT MOVES NORTH ACROSS THE MID ATLANTIC AND A COLD FRONT MOVES EAST ACROSS THE OHIO VALLEY. THE FRONT SHOULD MOVE THROUGH THE CWFA DURING THE DAY ON SUNDAY...BRINGING A CHANCE OF MUCH NEEDED PRECIPITATION. DIDN`T MAKE ANY CHANGES TO THE POPS FOR NOW...BUT MAY HAVE TO EVENTUALLY INCREASE THEM AS THE TIMING AND STRENGTH OF THE FRONT BECOME CLEARER. HIGH PRESSURE BUILDS BRIEFLY ON MONDAY...WITH ANOTHER COLD FRONT EXPECTED FOR THE MIDDLE OF THE WEEK. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... WINDS HAVE FINALLY SUBSIDED ACROSS THE REGION /OUTSIDE OF AREAS CLOSER TO THE CHESAPEAKE BAY/. THO MOST SITES ARE SHOWING WINDS NEAR 5KT OR LESS...A FAIRLY TURBULENT UPPER LOW STILL EXISTS TO THE NE WHICH WILL CONTINUE TO STREAM WAVES OF LOW LEVEL WINDS ACROSS THE MID ATLC /10-15KT/ AS THEY SLIDE ACROSS THE REGION OVERNIGHT. THESE CONDITIONS WILL ONLY INCREASE AFTER SUNRISE - W/ PEAK GUSTS BACK INTO THE 20-25KT RANGE THOUGH MORE INTERMITTENT THAN ON WED. MODELS SHOWING A SCT 6-8KFT DECK SCATTERED ABOUT THE AREA DURING THE DAYTIME HRS...SO SOLID VFR CONDITIONS WILL PERSIST THRU THE CURRENT TAF CYCLE. BREEZY NW WINDS WILL CONTINUE THROUGH FRIDAY AFTERNOON. SUB VFR CIGS/VSBYS POSSIBLE SATURDAY INTO SUNDAY AS A COLD FRONT CROSS THE AREA...ACCOMPANIED BY SCT CONVECTION. NW WINDS EXPECTED BEHIND THE FRONT. && .MARINE... SOLID SCA CONDITIONS WILL PERSIST INTO TODAY/TONIGHT AND FRI. INTERMITTENT PERIODS OF LOWER WIND VALUES /5-10KT/ WILL OCCUR DURING THIS TIME PERIOD...BUT THE WATERS WILL BE IN AT LEAST MARGINAL SCA WELL INTO FRI. THE UPPER LOW RESPONSIBLE FOR PUSHING THESE BREEZY CONDITIONS ACROSS THE REGION IS VERY SLOWLY DRIFTING OVER NRN NEW ENGLAND AND WILL FINALLY EXIT OFF THE COAST BY EARLY SAT. NW WINDS WILL CONTINUE ACROSS THE WATERS THROUGH FRIDAY AFTERNOON...AND TURN MORE NORTHERLY FRIDAY NIGHT. SMALL CRAFT CONDITIONS WILL CONTINUE THROUGH FRIDAY AFTERNOON...BUT DO EXPECT GUSTINESS TO DIMINISH AS AN UPPER LOW PUSHES EAST LATE FRIDAY INTO EARLY SATURDAY. A COLD FRONT WILL MOVE ACROSS THE WATERS ON SUNDAY...FOLLOWED BY HIGH PRESSURE ON MONDAY. && .FIRE WEATHER... FIRE WX STILL A CONCERN AFTER THE ROUGH CONDITIONS ON WED W/ DEWPOINTS IN THE 30S AND WIND GUSTS IN THE 25-35MPH RANGE...AND NOT TO MENTION HIGH TEMPS WELL INTO THE 90S. CONDITIONS THOUGH WILL BE A BIT LESS SEVERE FOR THU...W/ REL HUMIDITY VALUES IN THE 30S /AS OPPOSED TO THE TEENS/ - WIND GUSTS 20-25MPH AND HIGHS BARELY REACHING 80 BY MID AFTN. THESE CONDITIONS POINT MORE TO AN ENHANCED THREAT OF FIRE DANGER FOR TODAY...AS OPPOSED TO THE RED FLAG CONDITIONS OF YESTERDAY...THOUGH THE AREA REMAINS ABNORMALLY DRY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ530>534-537- 539>541-543. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ538-542. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ535- 536. && $$ SYNOPSIS...LISTEMAA NEAR TERM...GMS SHORT TERM...GMS LONG TERM...LISTEMAA AVIATION...GMS/LISTEMAA MARINE...GMS/LISTEMAA FIRE WEATHER...GMS 000 FXUS61 KPBZ 090516 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 116 AM EDT THU SEP 9 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY. THE NEXT CHANCE FOR WIDESPREAD RAIN WILL ARRIVE LATE SATURDAY AND SATURDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... AREA OF STRATOCU IS COVERING LOCATIONS FROM PIT NORTH. SOME DISAGREEMENT IN MODELS TODAY ON HOW LONG THESE CLOUDS WILL HANG AROUND AND HOW MUCH FURTHER SOUTH, IF AT ALL, THEY WILL MOVE. WILL KEEP MORE CLOUDS IN FOR LOCATIONS FROM PIT NORTH INTO THE AFTERNOON, WITH MS CONDITIONS TO THE SOUTH. THE TIGHT CUTOFF OF THE CLOUD COVER SHOULD LAST THROUGHOUT THE DAY. THIS WILL BE THE DIFFICULT PORTION OF TODAY`S FORECAST AND WILL NEED TO MONITORED. LOCATIONS ACROSS THE FAR NORTH COULD SEE A BRIEF SHOWER OR SPRINKLE THIS AFTERNOON, AS THE MID LEVEL FLOW MOVES RIGHT ACROSS THE LAKES AND ANOTHER SW WILL MOVE SOUTHEASTWARD ON THE BACK END OF THE TROUGH. TEMPERATURES WILL BE BELOW NORMAL TODAY. AND POSSIBLY MUCH BELOW, GREATER THAN 10 DEGREES, IN THOSE LOCATIONS WHICH HOLD ONTO THE CLOUD COVER. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... THE SHORTWAVE WILL SLOWLY PIVOT ON THE BACKSIDE OF UPPER LOW TONIGHT PUSHING MORE CLOUDS SOUTHWARD. AGAIN SOME DIFFERENCES IN MODEL SOLUTIONS HERE AS TROUGH RETROGRADES A BIT TONIGHT AND EARLY FRIDAY. THIS WILL KEEP CLOUD COVER IN FOR A PORTION OF THE MORNING HOURS FRIDAY. PIN POINTING EXACT LOCATION OF THE CLOUD DECK IS DIFFICULT AT THIS TIME. UPPER LOW EXITS FRIDAY NIGHT WITH RIDGE IN CONTROL THROUGH AT LEAST MID DAY SATURDAY. FRONTAL BOUNDARY WILL MOVE TOWARD THE REGION SATURDAY AFTERNOON. AT THIS POINT, LOW CONFIDENCE IN TIMING AND STRENGTH OF FRONT AS IT WILL BE RUNNING INTO EASTERN RIDGE AND WILL BE AIDED BY THE MOISTURE REMNANTS OF HERMINE. LITTLE CONSENSUS AT THIS TIME IN MODEL DATA, SO WILL TRY TO FIND A COMMON GROUND AND BRING THE CHANCE FOR SHOWERS IN SATURDAY AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... STRATOCUMULUS BKN/OVC WILL PREVAIL NORTH OF PIT FOR THE NEXT 24 HOURS...WITH PERIODS OF BROKEN FOR BVI/PIT/AGC/LBE AS WELL. FOR FKL/DUJ...CONDITIONS WILL LOWER TO MVFR LATE TNGT PERSISTING THROUGH THIS MORNING...IMPROVING TO VFR THIS AFTN BEFORE LOWERING TO MVFR AGAIN THURSDAY NIGHT. PIT/LBE/BVI/AGC WILL REMAIN VFR...WITH PORTS TO THE SOUTH REMAINING MOSTLY CLEAR. N/NW WINDS 3-6 KT TNGT WILL INCREASE TO 8-12 KT THIS AFTN WITH AN OCCASIONAL GUST TO 20 KT. HIGH PRESSURE WILL BUILD ACROSS THE AREA BY FRIDAY...WITH ALL PORTS BECOMING VFR. THE HIGH WILL EXIT SATURDAY...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. VFR CONDITIONS ARE EXPECTED TO RETURN ON MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 090241 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1041 PM EDT WED SEP 8 2010 .SYNOPSIS... A LOW PRESSURE SYSTEM REACHING THE CANADIAN MARITIMES WILL MOVE NORTHEAST OVERNIGHT. AN AREA OF HIGH PRESSURE WILL THEN GRADUALLY BUILD INTO OUR AREA THROUGH FRIDAY NIGHT. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY AND SATURDAY NIGHT. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT LATE TUESDAY OR TUESDAY NIGHT WILL BE FOLLOWED BY YET ANOTHER AREA OF HIGH PRESSURE WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A LARGE AND STRONG CYCLONIC FLOW CONTINUES ACROSS THE NORTHEAST AND MID ATLANTIC LATE THIS EVENING AS LOW PRESSURE IS SITUATED OVER NEW ENGLAND. IN ADDITION, THE WATER VAPOR IMAGERY SHOWS THE MAIN MIDLEVEL LOW NEARING NORTHERN NEW ENGLAND ATTM, HOWEVER THERE ARE SOME SHORT WAVES ROTATING AROUND THIS MAIN FEATURE. A SWATH OF CHANNELIZED VORTICITY IS SLIDING SOUTHEASTWARD FROM THE GREAT LAKES TO THE OFFSHORE AREAS OF SOUTHERN NEW ENGLAND. THIS IS FORECAST TO CONTINUE THROUGH THE OVERNIGHT AND SAG A LITTLE FARTHER SOUTHWARD WITH TIME. AN AREA OF DEEPER MOISTURE ALONG WITH CAA IS PRODUCING A WEALTH OF STRATOCUMULUS JUST TO OUR NORTHWEST. THIS MOISTURE IS BEING ADVECTED INTO THE SOUTHERN POCONOS AND FAR NORTHWESTERN NEW JERSEY. WHILE IT MAY HAVE A TOUGH TIME GETTING MUCH FARTHER SOUTH AND EAST OVERNIGHT DUE TO DOWNSLOPING, THE CHANNELIZED VORTICITY MAY END UP ENHANCING THIS CLOUD MASS SOME. THEREFORE, WE INCREASED THE SKY COVER SOME ACROSS THE FAR NORTHWESTERN ZONES. SOME LIGHT LAKE INDUCED SHOWERS ARE OCCURRING ACROSS WESTERN AND CENTRAL NEW YORK. WHILE SOME SPRINKLES MAY MAKE THEIR WAY TOWARD NORTHEASTERN PENNSYLVANIA LATER TONIGHT, WILL LEAVE OUT FOR NOW GIVEN THE UNCERTAINTY IN HOW FAR THEY ARE ABLE TO REACH. THE CAA COUPLED WITH ENOUGH WIND IN THE LOWER LEVELS OF THE ATMOSPHERE PLUS A TIGHT PRESSURE GRADIENT IS HOLDING THE WINDS UP. THE WINDS SHOULD DIMINISH A BIT MORE OVERNIGHT, BUT MOST PLACES ARE EXPECTED TO HAVE A BREEZE LINGERING THEREFORE THE WINDS WERE ADJUSTED UPWARD. THE TEMPERATURES AND DEW POINTS WERE ADJUSTED WITH THE 02Z OBSERVATIONS. SOME LOW TEMPERATURES WERE ADJUSTED DOWN SOME GIVEN THE CAA, TRENDS JUST TO OUR NORTHWEST AND THE NAM/GFS MOS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THIS TIME PERIOD. AN UPPER LOW PRESSURE SYSTEM ROTATING OVER NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES WILL BLOCK THE SURFACE HIGH FROM MOVING RAPIDLY EAST AND KEEP SOME CLOUDS AND WINDS OVER OUR AREA THROUGH FRIDAY. THERE WILL EVEN BE A SLIGHT CHANCE FOR A FEW LIGHT SHOWERS OR SPRINKLES IN THE NORTH THURSDAY AFTERNOON. TEMPERATURES BOTH THURSDAY AND FRIDAY WILL BE ON THE COOL SIDE WITH HIGHS IN THE 60S TO MID 70S. THE UPPER LOW WILL WEAKEN AND MOVE EAST FRIDAY NIGHT AND SATURDAY, ALLOWING THE SURFACE HIGH TO SETTLE OVER OUR AREA. THIS WILL MEAN DIMINISHING WINDS AND SKY COVER. LOWS THURSDAY NIGHT AND FRIDAY NIGHT WILL RANGE FROM THE MID AND UPPER 40S NORTH TO AROUND 60 IN THE SOUTHERN COASTAL AREAS. TEMPERATURES WILL BEGIN TO MODERATE SOMEWHAT SATURDAY WITH HIGHS MAINLY IN THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE FORECAST AREA HAS TO WAIT UNTIL THE BEGINNING OF THE EXTENDED PERIOD. MOISTURE FROM THE PLAINS STATES GETS CAUGHT UP WITH A DEVELOPING SFC WAVE/UPPER TROUGH ADVANCING FROM THE CENTRAL PART OF THE COUNTRY. THE MOISTURE IS FROM WHAT REMAIN OF FORMER TROPICAL STORM HERMINE...SO IT APPEARS THAT WE MAY GET MORE RAIN FROM THAT SYSTEM THEN FROM THE CLOSE-PASSING HURRICANE EARL EARLIER THIS MONTH. CHC POPS ARE IN THE FCST FOR SAT NGT THROUGH SUN NGT. THUNDER WAS RETAINED FOR SUN. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SFC HIGH PRESSURE FOLLOWS FOR MON WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SE FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SHOWERS TUE INTO WED. THE SYSTEM DOES NOT APPEAR TO BE A HEAVY RAIN MAKER...BUT JUST SOME SHOWERS EXPECTED. TEMPERATURES WILL BE CLOSE TO NORMAL DURING THE EXTENDED PERIOD. WE COULD GO THE ENTIRE PERIOD WITHOUT HAVING A 90 DEGREE DAY ACROSS THE REGION. THIS WOULD BE A DECENT CONTRAST TO THIS SUMMER AND THE FIRST EIGHT DAYS FOR SEPTEMBER. HIGHS WILL MOSTLY BE IN THE MID 70S TO LOW 80S AND OVERNIGHT LOWS IN THE 50S TO LOW 60S. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. SOME GUSTINESS WILL LINGER, ESPECIALLY AT PHL. OTHERWISE LIGHTER NW WINDS OVERNIGHT. NORTHWEST WINDS SHOULD PICK UP TO LEVELS CLOSE TO THOSE OF THIS AFTERNOON AFTER DAYBREAK THURSDAY. WE EXPECT LITTLE IN THE WAY OF CLOUDINESS THROUGH DAYBREAK THURSDAY, AFTER WHICH TIME A VFR STRATOCUMULUS DECK SHOULD DEVELOP. VISIBILITIES ARE EXPECTED TO BE VFR THROUGH THE TAF PERIOD. OUTLOOK... VFR FOR THURSDAY NIGHT /WHETHER OR NOT WE TRAP ANY STRATOCUMULUS UNDER AN INVERSION IS OPEN TO QUESTION, BUT NOT FORECAST AT THIS POINT/, THEN BREEZY CONDITIONS WITH VFR CEILINGS ARE EXPECTED ON FRIDAY. WINDS ARE EXPECTED TO DIMINISH ON FRIDAY NIGHT AND REMAIN LIGHT ON SATURDAY WITH CONTINUED VFR CONDITIONS. THE NEXT CHANCE FOR DEGRADED CONDITIONS IS ON SUNDAY. && .MARINE... WE SHOULD START TO LOSE OUR MARINE LAYER BY AROUND 03Z TONIGHT ON THE COLD AIR ADVECTION, AND WITH WINDS JUST ABOVE THE SURFACE IN SUPPORT OF GUSTS OF 25 KNOTS WE ARE GOING TO EXTEND THE ADVISORY INTO TONIGHT. THIS ADVISORY MAY NEED TO BE EXTENDED INTO OR THROUGH TOMORROW. THE GUIDANCE SHOWS MARGINAL ADVISORY GUSTS INTO THURSDAY EVENING WITH ANOTHER SHOT OF COLD AIR ADVECTION, ALTHOUGH THERE MAY BE A BIT OF A LULL IN THE WINDS PRIOR TO THEN. WE SHOULD START TO SEE CONDITIONS OVER THE WATERS RELAXING ON FRIDAY, WITH GOOD MARINE WEATHER INTO THE FIRST PART OF THE WEEKEND. SOME DETERIORATION IN CONDITIONS MAY OCCUR ON SUNDAY. && .FIRE WEATHER... WE ARE ANTICIPATING GUSTY WINDS AGAIN ON THURSDAY, ALTHOUGH NOT QUITE AS HIGH AS TODAY. WITH COOLER TEMPERATURES AND MORE CLOUD COVERAGE, ESPECIALLY NORTH, THE RELATIVE HUMIDITY VALUES ARE NOT FORECAST TO MEET WARNING CRITERIA. EVEN SO, THERE WILL BE AN INCREASED FIRE DANGER THREAT THURSDAY AFTERNOON. THIS WILL BE MENTIONED IN THE FIRE WEATHER FORECAST AND IN THE HWO. && .CLIMATE... PHL HAS TIED FOR THE YEAR WITH THE GREATEST NUMBER OF 90 DEGREE OR GREATER DAYS /53/, AND TTN /51/ AND ACY /44/ ARE OVER THE TOP. PLEASE SEE RERPHL, RERTTN AND RERACY FOR DETAILS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 4 AM EDT THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...RPW NEAR TERM...GORSE SHORT TERM...RPW LONG TERM...O`HARA AVIATION...DELISI MARINE...DELISI FIRE WEATHER...RPW CLIMATE...DELISI 000 FXUS61 KLWX 090058 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 858 PM EDT WED SEP 8 2010 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL BUILD IN TONIGHT AND PERSIST INTO THE WEEKEND. THE NEXT COLD FRONT WILL IMPACT THE REGION SUNDAY WHICH WILL BE BRIEFLY FOLLOWED BY HIGH PRESSURE. A DRY COLD FRONT IS THEN EXPECTED IN THE TUESDAY TIME FRAME. && .NEAR TERM /THROUGH THURSDAY/... SEE FIRE WX SECTION FOR DISCUSSION OF FIRE WX THREAT THRU THU. CDFNT CLEARING ST MARYS CNTY AND LWR PORTIONS OF MD CHESAPEAKE BAY AT 1Z. FOLLOWING FROPA...NW WINDS AND MUCH DRIER AIR FILTERING SWD...THO WINDS LESS GTY WITH WANING DIURNAL MIXING. TEMPS DROPPING RAPIDLY THIS EVE AFTR UNSEASONABLY WARM DAY. MAXIMA IN 90S...WITH 93 DEG HIGH AT KIAD TYING DAILY RECORD. HV BUMPED UP MINIMA JUST A BIT TNGT...AS DESPITE STRONG CAA...ATM WONT DECOUPLE AND WARMER THAN XPCD AFTN/EVE TEMPS MEANS FCST MINIMA WERE SOME 40-50 DEG COOLER THAN PREV MAXIMA OUT WEST. PREV DISCUSSION FOLLOWS... LOW PRESSURE WILL REMAIN OVER MAINE WHILE HIPRES CONTINUES TO BUILD INTO THE AREA ON THU. THE PRESSURE GRADIENT WILL NOT BE AS STRONG THU AS TDA...BUT NW WINDS WILL GUST AROUND 20 TO 25 MPH IN THE AFTN. DESPITE PLENTY OF SUNSHINE...TEMPS WILL STRUGGLE TO REACH THE 80 DEGREE MARK. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... THURSDAY NIGHT THROUGH FRIDAY NIGHT...AN A UPPER LOW PERSISTS ACROSS NEW ENGLAND AS A RIDGE AMPLIFIES AS IT DRIFTS EAST ACROSS THE MIDWEST. THIS PATTERN WILL MAINTAIN DRY NWLY FLOW WITH SUNNY/CLEAR CONDITIONS WITH MAX TEMPS LIMITED TO THE MID TO UPR 70S /AROUND FIVE DEGREES BELOW NORMAL/. MIN TEMPS A FEW DEGREES BELOW NORMAL BOTH NIGHTS...GENERALLY LOW TO MID 50S INLAND...UPR 50S FOR URBAN AREAS. SATURDAY...THE RIDGE AXIS BEGINS TO CROSS THE CWA WITH HIGH/MID CLOUDS SPREADING EAST. WARMER LOW LEVEL AIR SPREADS EAST WITH THE RIDGE...SO SHOULD NOT MANY OVERRUNNING CLOUDS BE PRESENT...MAX TEMPS SHOULD REACH THE LOW 80S EAST OF THE BLUE RIDGE /AND AROUND 80F ALONG WEST/. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT ASSOCIATED WITH A LOW OVER NRN ONTARIO LOOKS TO CROSS THE MID ATLANTIC LATER SUNDAY. INSTABILITY IN THE WARM SECTOR SHOULD ENABLE PREFRONTAL ACTIVITY THAT WOULD ENTER THE WRN ZONES EARLY SAT NIGHT...WHICH DEPENDING ON ORGANIZATION MAY REACH EAST OF THE BLUE RIDGE BEFORE DAYBREAK. WENT WITH HIGH CHANCE POPS LATE SATURDAY NIGHT OUT WEST...MID CHANCE /40 PERCENT/ EAST FOR SUNDAY. AFTER THE COLD FROPA SFC HIGH PRESSURE BRIEFLY BUILDS MONDAY BEFORE ANOTHER TROUGH CROSSES THE NERN CONUS...BRINGING A MAINLY DRY COLD FRONT IN THE TUESDAY TIMEFRAME. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... WIND GTS HV DIMINISHED AFTR SUNSET...BUT WILL RETURN BY MID-MRNG WITH SPEEDS OF 20-25 KT FROM NW FOR ALL XCPT KCHO. ASIDE FROM SOME CI...SKC AND P6SM VSBY XPCD INTO FRI. PREV DISCUSSION FOLLOWS... NWLY FLOW WITH VFR CONDS CONTINUES THUR NIGHT INTO THE WEEKEND. NEXT COLD FRONT AFFECTS THE AREA LATE SAT NIGHT THROUGH SUNDAY. HIGH PRESSURE BUILDS SUNDAY NIGHT AND MONDAY. && .MARINE... SCA CONDS HV ENDED...AT LEAST TEMPORARILY FOR THE WATERS. ADZY RMNS IN PLACE FOR MD PORTION OF CHESAPEAKE BAY AND LWR TIDAL POTOMAC RVR TNGT...WHERE NLY SURGE WILL PSBLY CREATE 20 KT GTS. TMW...INCRD MIXING WILL SUPPORT 20-25KT GTS FROM THE NW FOR THE ENTIRE WATERS...AND SCA IN EFFECT. PREV DISCUSSION FOLLOWS... LEFT SCA OUT OF THURSDAY NIGHT ATTM...THOUGH AN UPPER LOW OVER NEW ENGLAND WILL MAINTAIN A PRESSURE GRADIENT FOR NWLY FLOW ACROSS THE BAY THROUGH FRIDAY. HIGH PRESSURE RIDGE CROSSES ON SATURDAY WITH RETURN SLY FLOW STARTING LATE SATURDAY. THE NEXT COLD FRONT CROSSES THE BAY LATE SUNDAY...THOUGH PREFRONTAL SHOWERS AND STORMS COULD START EARLY SUNDAY. && .FIRE WEATHER... WINDS HAVE DIMINISHED BELOW RFW CRITERIA THIS EVE...SO WRNG ALLOWED TO EXPIRE AT 23Z. PREV DISCUSSION FOLLOWS... ***GOV OF W.V. HAS ISSUED A BURNING BAN FOR ERN WV PANHANDLE WHICH WILL CONTINUE UNTIL FURTHER NOTICE.*** EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE...GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. TIGHT PRESSURE GRADIENT WILL CONTINUE INTO THU AND FRI. WHILE NW WINDS /AROUND 10 TO 15 MPH/ ARE EXPECTED TO BE JUST BELOW RED FLAG WRNG CRITERIA ATTM...GUSTY WINDS AROUND 20 TO 25 MPH WILL KEEP AN ENHANCED FIRE WX THREAT DURING THE AFTERNOONS EACH DAY. WILL COORDINATE WITH FIRE OFFICIALS...BUT FEEL THAT AT LEAST AN SPS MENTIONING THE HEIGHTENED THREAT WILL BE NEEDED BOTH DAYS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>534- 537-539>541-543. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ535- 536-538-542. && $$ SYNOPSIS...BAJ NEAR TERM...JRK/SBK SHORT TERM...BAJ LONG TERM...BAJ AVIATION...BAJ/JRK/SBK MARINE...BAJ/JRK/SBK FIRE WEATHER...JRK/SBK 000 FXUS61 KAKQ 090012 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 812 PM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH OF THE REGION OVERNIGHT. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST ON SATURDAY... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... STILL A VERY STRONG GRADIENT OF LOW LVL MSTR IN PLACE ACRS THE MID ATLC REGION...DEW PTS HAVE MIXED OUT INTO THE 30S OVER THE DC AREA WITH A STRG NW FLOW...MEANWHILE ITS STILL IN THE 60S OVER CNTRL VA. EXPECT THE DEW PTS TO DROP FROM N TO S OVER THE NEXT SEVERAL HRS...BUT WITH LOSS OF DAYTIME HTG THEY`LL LIKELY DROP INTO THE UPR 40S TO LWR-MID 50S RATHER THAN THE 30S. ENOUGH OF A PRESSURE GRADIENT AND COOLER AIR ALOFT THAT SOME WIND SHOULD CONTINUE OVERNIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING OFF AS MUCH AS THEY OTHERWISE WOULD...LOWS RANGING FROM THE MID 50S OVER THE NRN PIEDMNT...UPR 50S TO LWR 60S OVER MUCH OF THE REMAINDER OF VA/MD...TO MID/UPR 60S NEAR THE SE VA/NE NC COAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH AN UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA...AND SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. THIS SHOULD YIELD DRY CONDITIONS AND MAINLY SUNNY SKIES (WITH SOME AFTN CU PRIMARILY OVER THE NRN ZONES). AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE MID/UPR 70S ACROSS THE NORTH TO LOW/MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. AFTERNOON DEW POINTS WILL DROP INTO THE 40S AND LOW 50S BOTH DAYS...YIELDING COMFORTABLE HUMIDITY LEVELS. SURFACE HIGH PRESSURE WILL LIKELY REMAIN OVER THE REGION FOR DRY WEATHER AGAIN ON SATURDAY. HOWEVER...THE NEXT SYSTEM WILL LIKELY BRING SOME CLOUDS TO THE AREA LATE IN THE DAY. MODELS KEEP PRECIP WEST OF OUR AREA THROUGH SATURDAY AFTERNOON...SO WILL CONTINUE WITH A DRY FORECAST FOR NOW. HIGH TEMPS WILL BE IN THE LOW/MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT APPROACHES FROM THE WEST SATURDAY NIGHT AND SUNDAY. CLOUDS WILL INCREASE AHEAD OF THE FRONT WITH A CHANCE FOR SHOWERS SUNDAY ALONG WITH THE POSSIBILITY OF THUNDER DURING THE AFTERNOON AND EVENING. CLOUD COVER SHOULD HOLD MAXIMUM TEMPERATURES IN THE LOW TO MID 80S. THE COLD FRONT CLEARS THE COAST LATER SUNDAY NIGHT WITH DRY AND MILD CONDITIONS PREVAILING EARLY NEXT WEEK WITH HIGH TEMPERATURES REMAINING THE LOW TO MID 80S...AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S. ANOTHER COLD FRONT APPROACHES THE MIDDLE OF NEXT WEEK WITH LITTLE INDICATION OF ANY MOISTURE. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... SKIES HAVE CLEARED ACRS NEARLY ALL OF THE CWA WITH THE NRN EDGE OF A CIRRUS BAND ACROSS SW VA AND NC DOWN TO ABOUT THE ALBEMARLE SOUND AS OF 23Z. THE HIGH CLOUDS WILL CONTINUE TO SINK TO THE SOUTH. VERY DRY BOUNDARY LAYER CONDITIONS WERE APPROACHING THE TAF SITES FROM THE NW AND THIS WILL PROMOTE CLEAR SKIES FOR THE TAF PERIOD. GUSTY WINDS OVER LAND AREAS WILL DIMINISH LATER THIS EVENING (WHILE INCREASING OVERNIGHT IN EXPOSED LOCATIONS NEAR THE BAY/COAST...SEE MARINE SECTION). NW WINDS WILL BECOME GUSTY ONCE AGAIN DURING THE AFTN ON THU BUT GENERALLY STAY BELOW 20 KNOTS...STRONGEST WINDS WILL BE AT SBY. VFR CONDITIONS SHOULD CONTINUE THU NIGHT THROUGH MON EXCEPT FOR A CHC OF TSTMS ASSOCIATED WITH THE NEXT COLD FRONT AROUND SUNDAY. && .MARINE... A DRY COLD FRONT CROSSES THE NORTHERN MARINE ZONES LATER THIS EVENING. THE AIRMASS BEHIND THE FRONT IS VERY DRY AND THIS SHOULD PRODUCE IDEAL MIXING WITH WATER TEMPERATURES AROUND 25-26C IN THE CHESAPEAKE BAY AND AROUND 24C IN THE ATLANTIC. FORECAST WIND SPEEDS AT 925MB IN THE NAM NEAR 30 KT ALONG AND IMMEDIATELY BEHIND THE FRONT OVER THE CHESAPEAKE BAY AND NORTHERNMOST COASTAL ZONES...SO A SMALL CRAFT FLAG HAS BEEN RAISED FOR THESE LOCATIONS BEGINNING AT 10 PM. THE FLAG FOR THE BAY EXTENDS FOR A FEW MORE HOURS BASED ON THE LOWER CRITERIA. THE MIXING PROFILE BECOMES MORE STABLE OVER THE WATER THURSDAY. HOWEVER...ANOTHER SURGE ARRIVES THURSDAY NIGHT. IT IS NOT QUITE AS STRONG...BUT WILL LIKELY PRODUCE ANOTHER ROUND OF SMALL CRAFT CONDITIONS FOR AT LEAST THE BAY. HIGH PRESSURE SLOWLY BUILDS IN FROM FRIDAY INTO SATURDAY WITH ANOTHER COLD FRONT APPROACHING SUNDAY. && .FIRE WEATHER... AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER ON THURSDAY... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS EXPECTED...WILL AGAIN HIGHLIGHT THE THREAT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON IN A SPECIAL WEATHER STATEMENT. THIS STATEMENT WILL INCLUDE ALL OF OUR COUNTIES IN VA EXCEPT FAR SE VA AND THE LOWER EASTERN SHORE. IT WILL ALSO INCLUDE THE LOWER MD EASTERN SHORE. AN ADDITIONAL STATEMENT MAY BE NECESSARY FOR FRIDAY AS CONDITIONS ARE EXPECTED TO BE SIMILAR TO THURSDAY. && .CLIMATE... WITH TODAY`S HIGH OF 90 F AT RICHMOND...THERE HAVE NOW BEEN 71 DAYS THIS YEAR WITH A HIGH OF 90 F OR HIGHER. THIS IS THE MOST ON RECORD AT RIC...SURPASSING THE 70 DAYS OF 90+ BACK IN 1977. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT THURSDAY FOR ANZ650-652. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THURSDAY FOR ANZ630>632. && $$ SYNOPSIS...JDM NEAR TERM...LKB SHORT TERM...JDM LONG TERM...AJZ AVIATION...LSA MARINE...AJZ FIRE WEATHER...JDM CLIMATE...LKB 000 FXUS61 KPHI 082354 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 754 PM EDT WED SEP 8 2010 .SYNOPSIS... A LOW PRESSURE SYSTEM REACHING THE CANADIAN MARITIMES WILL MOVE NORTHEAST OVERNIGHT. AN AREA OF HIGH PRESSURE WILL THEN GRADUALLY BUILD INTO OUR AREA THROUGH FRIDAY NIGHT. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY AND SATURDAY NIGHT. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT LATE TUESDAY OR TUESDAY NIGHT WILL BE FOLLOWED BY YET ANOTHER AREA OF HIGH PRESSURE WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... NOT TOO MANY CHANGES HAVE BEEN MADE TO THE GRIDS OVER THE LAST TWO SHORT TERM UPDATES. WE HAVE BEEN FOLLOWING AND ADVECTING AN AREA OF SUPER LOW DEW POINTS THRU OUR CWA. RELATIVE HUMIDITY LEVELS DROPPED IN THE TEENS ON ITS JOURNEY. OTHERWISE IT LOOKS AS THOUGH COMPLETE DECOUPLING WILL BE DIFFICULT AS THE GRADIENT BETWEEN THE DEPARTING LOW AND ADVANCING HIGH WILL BE TOO TIGHT (BOUNDARY LYR WINDS FCST TO REMAIN ABOVE 15 KTS) FOR THIS TO OCCUR. KIND OF A DIFFICULT MIN TEMP FCST AS DEW POINTS ARE PRETTY LOW EVEN IF THE WINDS DO NOT GO CALM. BECAUSE THEY WERE TRAILING OFF SLOWER THAN GUIDANCE WE DID BUMP THEM UP A BIT MAINLY IN URBAN AND COASTAL AREAS. EVEN THOUGH TEMPS YET AGAIN HIT 90 DEGREES TODAY, THE VISIBLE SATELLITE HAD A FALL LOOK TO IT TO OUR NW WITH AN OCEAN OF SC CLOUDS. IT LOOKS AS THOUGH THE SOUTHERN EXTENT IS ALONG THE PERIPHERY OF THE CHANNELIZED VORT MAX WHICH IF IT GOES ACCORDING TO PLAN SHOULD MAINLY AFFECT JUST OUR FAR NORTHERN CWA. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THIS TIME PERIOD. AN UPPER LOW PRESSURE SYSTEM ROTATING OVER NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES WILL BLOCK THE SURFACE HIGH FROM MOVING RAPIDLY EAST AND KEEP SOME CLOUDS AND WINDS OVER OUR AREA THROUGH FRIDAY. THERE WILL EVEN BE A SLIGHT CHANCE FOR A FEW LIGHT SHOWERS OR SPRINKLES IN THE NORTH THURSDAY AFTERNOON. TEMPERATURES BOTH THURSDAY AND FRIDAY WILL BE ON THE COOL SIDE WITH HIGHS IN THE 60S TO MID 70S. THE UPPER LOW WILL WEAKEN AND MOVE EAST FRIDAY NIGHT AND SATURDAY, ALLOWING THE SURFACE HIGH TO SETTLE OVER OUR AREA. THIS WILL MEAN DIMINISHING WINDS AND SKY COVER. LOWS THURSDAY NIGHT AND FRIDAY NIGHT WILL RANGE FROM THE MID AND UPPER 40S NORTH TO AROUND 60 IN THE SOUTHERN COASTAL AREAS. TEMPERATURES WILL BEGIN TO MODERATE SOMEWHAT SATURDAY WITH HIGHS MAINLY IN THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE FORECAST AREA HAS TO WAIT UNTIL THE BEGINNING OF THE EXTENDED PERIOD. MOISTURE FROM THE PLAINS STATES GETS CAUGHT UP WITH A DEVELOPING SFC WAVE/UPPER TROUGH ADVANCING FROM THE CENTRAL PART OF THE COUNTRY. THE MOISTURE IS FROM WHAT REMAIN OF FORMER TROPICAL STORM HERMINE...SO IT APPEARS THAT WE MAY GET MORE RAIN FROM THAT SYSTEM THEN FROM THE CLOSE-PASSING HURRICANE EARL EARLIER THIS MONTH. CHC POPS ARE IN THE FCST FOR SAT NGT THROUGH SUN NGT. THUNDER WAS RETAINED FOR SUN. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SFC HIGH PRESSURE FOLLOWS FOR MON WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SE FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SHOWERS TUE INTO WED. THE SYSTEM DOES NOT APPEAR TO BE A HEAVY RAIN MAKER...BUT JUST SOME SHOWERS EXPECTED. TEMPERATURES WILL BE CLOSE TO NORMAL DURING THE EXTENDED PERIOD. WE COULD GO THE ENTIRE PERIOD WITHOUT HAVING A 90 DEGREE DAY ACROSS THE REGION. THIS WOULD BE A DECENT CONTRAST TO THIS SUMMER AND THE FIRST EIGHT DAYS FOR SEPTEMBER. HIGHS WILL MOSTLY BE IN THE MID 70S TO LOW 80S AND OVERNIGHT LOWS IN THE 50S TO LOW 60S. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. SOME GUSTINESS MAY LINGER FOR A TIME THIS EVENING, ESPECIALLY AT PHL. OTHERWISE LIGHTER NW WINDS OVERNIGHT. NORTHWEST WINDS SHOULD PICK UP TO LEVELS CLOSE TO THOSE OF THIS AFTERNOON AFTER DAYBREAK THURSDAY. WE EXPECT LITTLE IN THE WAY OF CLOUDINESS THROUGH DAYBREAK THURSDAY, AFTER WHICH TIME A VFR STRATOCUMULUS DECK SHOULD DEVELOP. VISIBILITIES ARE EXPECTED TO BE VFR THROUGH THE TAF PERIOD. OUTLOOK... VFR FOR THURSDAY NIGHT /WHETHER OR NOT WE TRAP ANY STRATOCUMULUS UNDER AN INVERSION IS OPEN TO QUESTION, BUT NOT FORECAST AT THIS POINT/, THEN BREEZY CONDITIONS WITH VFR CEILINGS ARE EXPECTED ON FRIDAY. WINDS ARE EXPECTED TO DIMINISH ON FRIDAY NIGHT AND REMAIN LIGHT ON SATURDAY WITH CONTINUED VFR CONDITIONS. THE NEXT CHANCE FOR DEGRADED CONDITIONS IS ON SUNDAY. && .MARINE... WE SHOULD START TO LOSE OUR MARINE LAYER BY AROUND 03Z TONIGHT ON THE COLD AIR ADVECTION, AND WITH WINDS JUST ABOVE THE SURFACE IN SUPPORT OF GUSTS OF 25 KNOTS WE ARE GOING TO EXTEND THE ADVISORY INTO TONIGHT. THIS ADVISORY MAY NEED TO BE EXTENDED INTO OR THROUGH TOMORROW. THE GUIDANCE SHOWS MARGINAL ADVISORY GUSTS INTO THURSDAY EVENING WITH ANOTHER SHOT OF COLD AIR ADVECTION, ALTHOUGH THERE MAY BE A BIT OF A LULL IN THE WINDS PRIOR TO THEN. WE SHOULD START TO SEE CONDITIONS OVER THE WATERS RELAXING ON FRIDAY, WITH GOOD MARINE WEATHER INTO THE FIRST PART OF THE WEEKEND. SOME DETERIORATION IN CONDITIONS MAY OCCUR ON SUNDAY. && .FIRE WEATHER... WE ARE ANTICIPATING GUSTY WINDS AGAIN ON THURSDAY, ALTHOUGH NOT QUITE AS HIGH AS TODAY. WITH COOLER TEMPERATURES AND MORE CLOUD COVERAGE, ESPECIALLY NORTH, THE RELATIVE HUMIDITY VALUES ARE NOT FORECAST TO MEET WARNING CRITERIA. EVEN SO, THERE WILL BE AN INCREASED FIRE DANGER THREAT THURSDAY AFTERNOON. THIS WILL BE MENTIONED IN THE FIRE WEATHER FORECAST AND IN THE HWO. && .CLIMATE... PHL HAS TIED FOR THE YEAR WITH THE GREATEST NUMBER OF 90 DEGREE OR GREATER DAYS /53/, AND TTN /51/ AND ACY /44/ ARE OVER THE TOP. PLEASE SEE RERPHL, RERTTN AND RERACY FOR DETAILS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 4 AM EDT THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...RPW NEAR TERM...GIGI SHORT TERM...RPW LONG TERM...O`HARA AVIATION...DELISI MARINE...DELISI FIRE WEATHER...RPW CLIMATE...RPW 000 FXUS61 KPBZ 082321 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 721 PM EDT WED SEP 8 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY WITH THE NEXT CHANCE OF SIGNIFICANT RAIN LATE SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... STRATOCU HAS REACHED TO JUST NORTH OF KPIT THIS AFTERNOON AND BULK OF THIS WILL DISSIPATE THIS EVENING EXCEPT ACROSS THE FAR NORTH WHERE FLOW OFF THE LAKES WILL KEEP SOME CLOUDS IN OVERNIGHT. NORTHWEST FLOW WILL CONTINUE ACROSS REGION INTO THURSDAY AS UPPER LEVEL LOW WOBBLES ACROSS NEW ENGLAND. TEMPERATURES CLOSE TO MODEL MOS. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... SHORTWAVE WILL PIVOT ON THE BACKSIDE OF UPPER LOW THURSDAY NIGHT WITH SOME CLOUDS MAINLY NORTH AND POSSIBLE SPRINKLE. UPPER LOW THEN EXITS FRIDAY WITH RIDGE IN CONTROL UNTIL LATE SATURDAY. ON SATURDAY A WARM FRONT AHEAD OF AN UPPER TROUGH FROM THE PLAINS WILL INCREASE CLOUDS AND BRING WARMER TEMPERATURES. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. GENERALLY IN AGREEMENT WITH HPC PROGS. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... STRATOCUMULUS WILL REMAIN ALONG THE I-80 CORRIDOR...KEEPING CEILINGS AT FKL AND DUJ THROUGH THE ENTIRE TAF PERIOD. CLOUDS SHOULD LOWER TO MVFR OVERNIGHT...SLOWLY RISING BACK TO VFR BY EARLY AFTERNOON. WITH BVI ALONG THE EDGE OF THE CLOUD DECK TODAY...CANNOT RULE OUT THE POSSIBILITY THAT SOME MVFR CIGS COULD DEVELOP THERE AS WELL OVERNIGHT. ELSEWHERE...EXPECT CLEAR SKIES OVERNIGHT WITH WINDS REMAINING STRONG ENOUGH TO LIMIT FOG DEVELOPMENT. WINDS WILL CONTINUE TO BE OUT OF THE NORTHWEST...WITH SOME 15 KT GUSTS POSSIBLE ON THURSDAY...BUT NOT AS HIGH AS THE 20-25 KT GUSTS SEEN TODAY. VFR WILL PREVAIL FOR FRIDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. VFR CONDITIONS ARE EXPECTED TO RETURN ON MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 082307 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 707 PM EDT WED SEP 8 2010 .SYNOPSIS... THE COLD FRONT WILL MOVE OFF TO THE EAST TONIGHT AS LOW PRESSURE CROSSES NORTHERN NEW ENGLAND. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA THROUGH FRIDAY NIGHT. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY AND SATURDAY NIGHT. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT LATE TUESDAY OR TUESDAY NIGHT WILL BE FOLLOWED BY YET ANOTHER AREA OF HIGH PRESSURE WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... THE COLD FRONT IS HAVING A DIFFICULT TIME MOVING OFF TO THE EAST THIS AFTERNOON, ALTHOUGH SKIES HAVE CLEARED AND MUCH DRIER AIR HAS PUSHED INTO ALL BUT THE EXTREME SOUTHERN COASTAL SECTIONS. THE DOWNSLOPING WEST TO WEST NORTHWEST WINDS HAVE ALLOWED TEMPERATURES TO CLIMB WELL INTO THE 80S AND LOWER 90S IN ALL BUT OUR NORTHERN MOUNTAIN AREAS. AS THE FRONT MOVES OFF TO THE EAST TONIGHT, WINDS WILL DROP OFF TO 5 TO 10 MPH. SKIES WILL BE MAINLY CLEAR EXCEPT FOR A FEW CLOUDS IN THE EXTREME NORTH. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE UPPER 40S IN THE MOUNTAINS TO THE LOWER 60S ALONG THE COAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THIS TIME PERIOD. AN UPPER LOW PRESSURE SYSTEM ROTATING OVER NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES WILL BLOCK THE SURFACE HIGH FROM MOVING RAPIDLY EAST AND KEEP SOME CLOUDS AND WINDS OVER OUR AREA THROUGH FRIDAY. THERE WILL EVEN BE A SLIGHT CHANCE FOR A FEW LIGHT SHOWERS OR SPRINKLES IN THE NORTH THURSDAY AFTERNOON. TEMPERATURES BOTH THURSDAY AND FRIDAY WILL BE ON THE COOL SIDE WITH HIGHS IN THE 60S TO MID 70S. THE UPPER LOW WILL WEAKEN AND MOVE EAST FRIDAY NIGHT AND SATURDAY, ALLOWING THE SURFACE HIGH TO SETTLE OVER OUR AREA. THIS WILL MEAN DIMINISHING WINDS AND SKY COVER. LOWS THURSDAY NIGHT AND FRIDAY NIGHT WILL RANGE FROM THE MID AND UPPER 40S NORTH TO AROUND 60 IN THE SOUTHERN COASTAL AREAS. TEMPERATURES WILL BEGIN TO MODERATE SOMEWHAT SATURDAY WITH HIGHS MAINLY IN THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE FORECAST AREA HAS TO WAIT UNTIL THE BEGINNING OF THE EXTENDED PERIOD. MOISTURE FROM THE PLAINS STATES GETS CAUGHT UP WITH A DEVELOPING SFC WAVE/UPPER TROUGH ADVANCING FROM THE CENTRAL PART OF THE COUNTRY. THE MOISTURE IS FROM WHAT REMAIN OF FORMER TROPICAL STORM HERMINE...SO IT APPEARS THAT WE MAY GET MORE RAIN FROM THAT SYSTEM THEN FROM THE CLOSE-PASSING HURRICANE EARL EARLIER THIS MONTH. CHC POPS ARE IN THE FCST FOR SAT NGT THROUGH SUN NGT. THUNDER WAS RETAINED FOR SUN. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SFC HIGH PRESSURE FOLLOWS FOR MON WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SE FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SHOWERS TUE INTO WED. THE SYSTEM DOES NOT APPEAR TO BE A HEAVY RAIN MAKER...BUT JUST SOME SHOWERS EXPECTED. TEMPERATURES WILL BE CLOSE TO NORMAL DURING THE EXTENDED PERIOD. WE COULD GO THE ENTIRE PERIOD WITHOUT HAVING A 90 DEGREE DAY ACROSS THE REGION. THIS WOULD BE A DECENT CONTRAST TO THIS SUMMER AND THE FIRST EIGHT DAYS FOR SEPTEMBER. HIGHS WILL MOSTLY BE IN THE MID 70S TO LOW 80S AND OVERNIGHT LOWS IN THE 50S TO LOW 60S. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A WEST TO NORTHWEST WIND GUSTING INTO THE MID TO UPPER 20 KNOTS RANGE SHOULD GO TO NORTHWEST AT AROUND 10 KNOTS BY AROUND DUSK. SOME GUSTINESS MAY LINGER FOR A TIME, ESPECIALLY AT PHL. NORTHWEST WINDS SHOULD PICK UP TO LEVELS CLOSE TO THOSE OF THIS AFTERNOON AFTER DAYBREAK THURSDAY. WE EXPECT LITTLE IN THE WAY OF CLOUDINESS THROUGH DAYBREAK THURSDAY, AFTER WHICH TIME A VFR STRATOCUMULUS DECK SHOULD DEVELOP. VISIBILITIES ARE EXPECTED TO BE VFR THROUGH THE TAF PERIOD. OUTLOOK... VFR FOR THURSDAY NIGHT /WHETHER OR NOT WE TRAP ANY STRATOCUMULUS UNDER AN INVERSION IS OPEN TO QUESTION, BUT NOT FORECAST AT THIS POINT/, THEN BREEZY CONDITIONS WITH VFR CEILINGS ARE EXPECTED ON FRIDAY. WINDS ARE EXPECTED TO DIMINISH ON FRIDAY NIGHT AND REMAIN LIGHT ON SATURDAY WITH CONTINUED VFR CONDITIONS. THE NEXT CHANCE FOR DEGRADED CONDITIONS IS ON SUNDAY. && .MARINE... WE SHOULD START TO LOSE OUR MARINE LAYER BY AROUND 03Z TONIGHT ON THE COLD AIR ADVECTION, AND WITH WINDS JUST ABOVE THE SURFACE IN SUPPORT OF GUSTS OF 25 KNOTS WE ARE GOING TO EXTEND THE ADVISORY INTO TONIGHT. THIS ADVISORY MAY NEED TO BE EXTENDED INTO OR THROUGH TOMORROW. THE GUIDANCE SHOWS MARGINAL ADVISORY GUSTS INTO THURSDAY EVENING WITH ANOTHER SHOT OF COLD AIR ADVECTION, ALTHOUGH THERE MAY BE A BIT OF A LULL IN THE WINDS PRIOR TO THEN. WE SHOULD START TO SEE CONDITIONS OVER THE WATERS RELAXING ON FRIDAY, WITH GOOD MARINE WEATHER INTO THE FIRST PART OF THE WEEKEND. SOME DETERIORATION IN CONDITIONS MAY OCCUR ON SUNDAY. && .FIRE WEATHER... THE RED FLAG WARNING WAS ALLOWED TO EXPIRE AT 7PM. WINDS ARE IN THE PROCESS OF DECREASING RAPIDLY AND WHILE A FEW PLACES ARE STILL CURRENTLY REACHING WARNING CRITERIA, THE DOWNWARD WIND TREND WAS INCREASING AND WE EXPECT THE WIND CRITERIA TO NOT BE MET FOR MUCH LONGER. RELATIVE HUMIDITY LEVELS WILL ALSO RISE OVERNIGHT. WE ARE ANTICIPATING GUSTY WINDS AGAIN ON THURSDAY, ALTHOUGH NOT QUITE AS HIGH AS TODAY. WITH COOLER TEMPERATURES AND MORE CLOUD COVERAGE, ESPECIALLY NORTH, THE RELATIVE HUMIDITY VALUES ARE NOT FORECAST TO MEET WARNING CRITERIA. EVEN SO, THERE WILL BE AN INCREASED FIRE DANGER THREAT THURSDAY AFTERNOON. THIS WILL BE MENTIONED IN THE FIRE WEATHER FORECAST AND IN THE HWO. && .CLIMATE... PHL HAS TIED FOR THE YEAR WITH THE GREATEST NUMBER OF 90 DEGREE OR GREATER DAYS /53/, AND TTN /51/ AND ACY /44/ ARE OVER THE TOP. PLEASE SEE RERPHL, RERTTN AND RERACY FOR DETAILS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 4 AM EDT THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...RPW NEAR TERM...RPW SHORT TERM...RPW LONG TERM...O`HARA AVIATION...DELISI MARINE...DELISI FIRE WEATHER...RPW/GIGI CLIMATE...DELISI 000 FXUS61 KAKQ 082049 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 449 PM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH OF THE REGION THROUGH TONIGHT. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST ON SATURDAY... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A RELATIVELY DRY COLD FRONT IS MAKING ITS WAY ACROSS THE REGION THIS AFTERNOON. THE FRONT HAS TRIGGERED SOME ISOLATED SHWR ACTIVITY ACROSS OUR SW ZONES...BUT NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION AS THESE SHWRS SLOWLY DIE OUT AND DRIFT SOUTH THROUGH THE EVENING. THERE IS A VERY DISTINCT BACK EDGE TO THE CLOUD DECK NOTED ON CURRENT VISIBLE SATELLITE PICS. THE BACK EDGE WILL PUSH SOUTH OF THE RICHMOND METRO BY MID-AFTERNOON...AND AS THE FRONT CONTINUES TO DRIFT SOUTH...THE CLOUDS SHOULD MOVE OUT OF OUR CWA AROUND OR JUST AFTER SUNSET SETTING THE STAGE FOR A CLEAR SKY TONIGHT. A NOTICEABLE DROP IN DEW POINTS (MID-40S TO MID-50S) IS NOTED OVER THE MD/WV PANHANDLES AND NORTHERN VA THIS AFTERNOON... AND THIS DRIER AIR WILL CONTINUE TO WORK SOUTHWARD INTO OUR AREA TONIGHT. WITH A CLEAR SKY...LIGHT WINDS AND DRIER AIR IN PLACE TONIGHT...EXPECTING PLEASANT CONDITIONS. LOWS WILL FALL INTO THE 50S TO NEAR 60 INLAND WITH MID/UPR 60S NEAR THE COAST. WINDS WILL DIMINISH AROUND SUNSET. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH AN UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE MID/UPR 70S ACROSS THE NORTH TO LOW/MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. AFTERNOON DEW POINTS WILL DROP INTO THE 40S AND LOW 50S BOTH DAYS...YIELDING COMFORTABLE HUMIDITY LEVELS. SURFACE HIGH PRESSURE WILL LIKELY REMAIN OVER THE REGION FOR DRY WEATHER AGAIN ON SATURDAY. HOWEVER...THE NEXT SYSTEM WILL LIKELY BRING SOME CLOUDS TO THE AREA LATE IN THE DAY. MODELS KEEP PRECIP WEST OF OUR AREA THROUGH SATURDAY AFTERNOON...SO WILL CONTINUE WITH A DRY FORECAST FOR NOW. HIGH TEMPS WILL BE IN THE LOW/MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT APPROACHES FROM THE WEST SATURDAY NIGHT AND SUNDAY. CLOUDS WILL INCREASE AHEAD OF THE FRONT WITH A CHANCE FOR SHOWERS SUNDAY ALONG WITH THE POSSIBILITY OF THUNDER DURING THE AFTERNOON AND EVENING. CLOUD COVER SHOULD HOLD MAXIMUM TEMPERATURES IN THE LOW TO MID 80S. THE COLD FRONT CLEARS THE COAST LATER SUNDAY NIGHT WITH DRY AND MILD CONDITIONS PREVAILING EARLY NEXT WEEK WITH HIGH TEMPERATURES REMAINING THE LOW TO MID 80S...AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S. ANOTHER COLD FRONT APPROACHES THE MIDDLE OF NEXT WEEK WITH LITTLE INDICATION OF ANY MOISTURE. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... A DRY COLD FRONT CROSSES THE NORTHERN MARINE ZONES LATER THIS EVENING. THE AIRMASS BEHIND THE FRONT IS VERY DRY AND THIS SHOULD PRODUCE IDEAL MIXING WITH WATER TEMPERATURES AROUND 25-26C IN THE CHESAPEAKE BAY AND AROUND 24C IN THE ATLANTIC. FORECAST WIND SPEEDS AT 925MB IN THE NAM NEAR 30 KT ALONG AND IMMEDIATELY BEHIND THE FRONT OVER THE CHESAPEAKE BAY AND NORTHERNMOST COASTAL ZONES...SO A SMALL CRAFT FLAG HAS BEEN RAISED FOR THESE LOCATIONS BEGINNING AT 10 PM. THE FLAG FOR THE BAY EXTENDS FOR A FEW MORE HOURS BASED ON THE LOWER CRITERIA. THE MIXING PROFILE BECOMES MORE STABLE OVER THE WATER THURSDAY. HOWEVER...ANOTHER SURGE ARRIVES THURSDAY NIGHT. IT IS NOT QUITE AS STRONG...BUT WILL LIKELY PRODUCE ANOTHER ROUND OF SMALL CRAFT CONDITIONS FOR AT LEAST THE BAY. HIGH PRESSURE SLOWLY BUILDS IN FROM FRIDAY INTO SATURDAY WITH ANOTHER COLD FRONT APPROACHING SUNDAY. && .FIRE WEATHER... WILL CONTINUE WITH A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER ACROSS OUR NORTHERN COUNTIES IN VA AND INTO THE LOWER MD EASTERN SHORE THROUGH 7PM. RH VALUES DROPPING INTO THE 30S WITH CLEAR SKIES AND WIND GUSTS TO 25 MPH WILL ENHANCE THE THREAT FOR WILDFIRES IN THESE AREAS TIL 7PM. AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER ON THURSDAY... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS EXPECTED...WILL AGAIN HIGHLIGHT THE THREAT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON IN A SPECIAL WEATHER STATEMENT. THIS STATEMENT WILL INCLUDE ALL OF OUR COUNTIES IN VA EXCEPT SE VA AND THE LOWER EASTERN SHORE. IT WILL ALSO INCLUDE THE LOWER MD EASTERN SHORE. AN ADDITIONAL STATEMENT MAY BE NECESSARY FOR FRIDAY AS CONDITIONS ARE EXPECTED TO BE SIMILAR TO THURSDAY. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 5 AM EDT THURSDAY FOR ANZ650-652. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EDT THURSDAY FOR ANZ630>632. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...JDM LONG TERM...AJZ AVIATION...JEF MARINE...AJZ/JEF FIRE WEATHER...JDM 000 FXUS61 KPHI 081929 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 329 PM EDT WED SEP 8 2010 .SYNOPSIS... THE COLD FRONT WILL MOVE OFF TO THE EAST TONIGHT AS LOW PRESSURE CROSSES NORTHERN NEW ENGLAND. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA THROUGH FRIDAY NIGHT. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY AND SATURDAY NIGHT. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY FOLLOWED BY HIGH PRESSURE MONDAY INTO TUESDAY. A WEAK COLD FRONT LATE TUESDAY OR TUESDAY NIGHT WILL BE FOLLOWED BY YET ANOTHER AREA OF HIGH PRESSURE WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY/... THE COLD FRONT IS HAVING A DIFFICULT TIME MOVING OFF TO THE EAST THIS AFTERNOON, ALTHOUGH SKIES HAVE CLEARED AND MUCH DRIER AIR HAS PUSHED INTO ALL BUT THE EXTREME SOUTHERN COASTAL SECTIONS. THE DOWNSLOPING WEST TO WEST NORTHWEST WINDS HAVE ALLOWED TEMPERATURES TO CLIMB WELL INTO THE 80S AND LOWER 90S IN ALL BUT OUR NORTHERN MOUNTAIN AREAS. AS THE FRONT MOVES OFF TO THE EAST TONIGHT, WINDS WILL DROP OFF TO 5 TO 10 MPH. SKIES WILL BE MAINLY CLEAR EXCEPT FOR A FEW CLOUDS IN THE EXTREME NORTH. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE UPPER 40S IN THE MOUNTAINS TO THE LOWER 60S ALONG THE COAST. && .SHORT TERM /6 AM THURSDAY THROUGH SATURDAY/... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THIS TIME PERIOD. AN UPPER LOW PRESSURE SYSTEM ROTATING OVER NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES WILL BLOCK THE SURFACE HIGH FROM MOVING RAPIDLY EAST AND KEEP SOME CLOUDS AND WINDS OVER OUR AREA THROUGH FRIDAY. THERE WILL EVEN BE A SLIGHT CHANCE FOR A FEW LIGHT SHOWERS OR SPRINKLES IN THE NORTH THURSDAY AFTERNOON. TEMPERATURES BOTH THURSDAY AND FRIDAY WILL BE ON THE COOL SIDE WITH HIGHS IN THE 60S TO MID 70S. THE UPPER LOW WILL WEAKEN AND MOVE EAST FRIDAY NIGHT AND SATURDAY, ALLOWING THE SURFACE HIGH TO SETTLE OVER OUR AREA. THIS WILL MEAN DIMINISHING WINDS AND SKY COVER. LOWS THURSDAY NIGHT AND FRIDAY NIGHT WILL RANGE FROM THE MID AND UPPER 40S NORTH TO AROUND 60 IN THE SOUTHERN COASTAL AREAS. TEMPERATURES WILL BEGIN TO MODERATE SOMEWHAT SATURDAY WITH HIGHS MAINLY IN THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE NEXT CHANCE FOR SHOWERS ACROSS THE FORECAST AREA HAS TO WAIT UNTIL THE BEGINNING OF THE EXTENDED PERIOD. MOISTURE FROM THE PLAINS STATES GETS CAUGHT UP WITH A DEVELOPING SFC WAVE/UPPER TROUGH ADVANCING FROM THE CENTRAL PART OF THE COUNTRY. THE MOISTURE IS FROM WHAT REMAIN OF FORMER TROPICAL STORM HERMINE...SO IT APPEARS THAT WE MAY GET MORE RAIN FROM THAT SYSTEM THEN FROM THE CLOSE-PASSING HURRICANE EARL EARLIER THIS MONTH. CHC POPS ARE IN THE FCST FOR SAT NGT THROUGH SUN NGT. THUNDER WAS RETAINED FOR SUN. A WESTERLY UPPER FLOW DEVELOPS BEHIND THE SUNDAY SYSTEM AND SFC HIGH PRESSURE FOLLOWS FOR MON WITH DRY WEATHER EXPECTED. ANOTHER WEAK SYSTEM MOVES SE FROM THE GREAT LAKES BRINGING ANOTHER CHC FOR SHOWERS TUE INTO WED. THE SYSTEM DOES NOT APPEAR TO BE A HEAVY RAIN MAKER...BUT JUST SOME SHOWERS EXPECTED. TEMPERATURES WILL BE CLOSE TO NORMAL DURING THE EXTENDED PERIOD. WE COULD GO THE ENTIRE PERIOD WITHOUT HAVING A 90 DEGREE DAY ACROSS THE REGION. THIS WOULD BE A DECENT CONTRAST TO THIS SUMMER AND THE FIRST EIGHT DAYS FOR SEPTEMBER. HIGHS WILL MOSTLY BE IN THE MID 70S TO LOW 80S AND OVERNIGHT LOWS IN THE 50S TO LOW 60S. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A WEST TO NORTHWEST WIND GUSTING INTO THE MID TO UPPER 20 KNOTS RANGE SHOULD GO TO NORTHWEST AT AROUND 10 KNOTS BY AROUND DUSK. SOME GUSTINESS MAY LINGER FOR A TIME, ESPECIALLY AT PHL. NORTHWEST WINDS SHOULD PICK UP TO LEVELS CLOSE TO THOSE OF THIS AFTERNOON AFTER DAYBREAK THURSDAY. WE EXPECT LITTLE IN THE WAY OF CLOUDINESS THROUGH DAYBREAK THURSDAY, AFTER WHICH TIME A VFR STRATOCUMULUS DECK SHOULD DEVELOP. VISIBILITIES ARE EXPECTED TO BE VFR THROUGH THE TAF PERIOD. OUTLOOK... VFR FOR THURSDAY NIGHT /WHETHER OR NOT WE TRAP ANY STRATOCUMULUS UNDER AN INVERSION IS OPEN TO QUESTION, BUT NOT FORECAST AT THIS POINT/, THEN BREEZY CONDITIONS WITH VFR CEILINGS ARE EXPECTED ON FRIDAY. WINDS ARE EXPECTED TO DIMINISH ON FRIDAY NIGHT AND REMAIN LIGHT ON SATURDAY WITH CONTINUED VFR CONDITIONS. THE NEXT CHANCE FOR DEGRADED CONDITIONS IS ON SUNDAY. && .MARINE... WE SHOULD START TO LOSE OUR MARINE LAYER BY AROUND 03Z TONIGHT ON THE COLD AIR ADVECTION, AND WITH WINDS JUST ABOVE THE SURFACE IN SUPPORT OF GUSTS OF 25 KNOTS WE ARE GOING TO EXTEND THE ADVISORY INTO TONIGHT. THIS ADVISORY MAY NEED TO BE EXTENDED INTO OR THROUGH TOMORROW. THE GUIDANCE SHOWS MARGINAL ADVISORY GUSTS INTO THURSDAY EVENING WITH ANOTHER SHOT OF COLD AIR ADVECTION, ALTHOUGH THERE MAY BE A BIT OF A LULL IN THE WINDS PRIOR TO THEN. WE SHOULD START TO SEE CONDITIONS OVER THE WATERS RELAXING ON FRIDAY, WITH GOOD MARINE WEATHER INTO THE FIRST PART OF THE WEEKEND. SOME DETERIORATION IN CONDITIONS MAY OCCUR ON SUNDAY. && .FIRE WEATHER... EXTREMELY DRY AIR MOVED IN THIS AFTERNOON FOLLOWING THE FRONTAL PASSAGE. THIS DRY AIR, COMBINED WITH VERY LOW FUEL MOISTURE AND WINDS GUSTING AT TIMES TO AROUND 30 MPH, JUSTIFIED OUR RED FLAG WARNING. THE WARNING WILL CONTINUE UNTIL 7 PM THIS EVENING. WE ARE ANTICIPATING GUSTY WINDS AGAIN ON THURSDAY, ALTHOUGH NOT QUITE AS HIGH AS TODAY. WITH COOLER TEMPERATURES AND MORE CLOUD COVERAGE, ESPECIALLY NORTH, THE RELATIVE HUMIDITY VALUES ARE NOT FORECAST TO MEET WARNING CRITERIA. EVEN SO, THERE WILL BE AN INCREASED FIRE DANGER THREAT THURSDAY AFTERNOON. THIS WILL BE MENTIONED IN THE FIRE WEATHER FORECAST AND IN THE HWO. && .CLIMATE... PHL HAS TIED FOR THE YEAR WITH THE GREATEST NUMBER OF 90 DEGREE OR GREATER DAYS /53/, AND TTN /51/ AND ACY /44/ ARE OVER THE TOP. PLEASE SEE RERPHL, RERTTN AND RERACY FOR DETAILS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR PAZ060-061- 067>071. NJ...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NJZ009-010- 012>027. DE...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MDZ008-012- 015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 4 AM EDT THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...RPW NEAR TERM...RPW SHORT TERM...RPW LONG TERM...O`HARA AVIATION...DELISI MARINE...DELISI FIRE WEATHER...RPW CLIMATE...DELISI 000 FXUS61 KLWX 081928 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 328 PM EDT WED SEP 8 2010 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL BUILD IN TONIGHT AND PERSIST INTO THE WEEKEND. THE NEXT COLD FRONT WILL IMPACT THE REGION SUNDAY WHICH WILL BE BRIEFLY FOLLOWED BY HIGH PRESSURE. A DRY COLD FRONT IS THEN EXPECTED IN THE TUESDAY TIMEFRAME. && .NEAR TERM /THROUGH THURSDAY/... SEE FIRE WX SECTION FOR DISCUSSION OF FIRE WX THREAT FOR TDA AND AGAIN TOMORROW. COLD FRONT/SFC TROUGH HAS JUST ABOUT CLEARED THE AREA WITH THE EXCEPTION OF THE NRN PIEDMONT AND LOWER SRN MD. A SIGNIFICANT DROP IN DEWPOINTS AND INCREASE IN WINDS ARE NOTED BEHIND THE FRONT. USED 3KM HRRR WRF TO POPULATE DEWPOINT GRIDS THRU THIS EVE. HRRR WRF WAS THE ONLY MODEL THAT WAS ABLE TO PICK UP ON THE LARGE DROP IN DEWPOINTS IN THE 30S AND LOW 40S. BREEZY WINDS WITH GUSTS OF 30 TO 35 MPH WILL CONTINUE THRU THE AFTN...BEFORE RELAXING A BIT TOWARD SUNSET. DESPITE A HOT DAY TDA...NW FLOW WILL BRING IN A SURGE OF COLDER AIR TNGT...CAUSING OVNGT MIN TEMPS TO DROP INTO THE U30S ACROSS THE WRN SLOPES OF THE ALLEGHENY FRONT/ MID AND UPPER 50S ALONG AND EAST OF I-95. STRONG PRESSURE GRADIENT BETWEEN LOPRES NEAR THE MAINE/CANADA BORDER AND HIPRES BUILDING IN FROM THE GREAT PLAINS...AND STEEPENING LAPSE RATES WILL PREVENT WINDS FROM DECOUPLING ACROSS THE ENTIRE AREA...ESPECIALLY ACROSS THE RIDGE TOPS. DESPITE LOWS FALLING INTO THE UPPER 30S IN THE FAR WEST...A BREEZE SHOULD PREVENT FROST FROM FORMING. LOW PRESSURE WILL REMAIN OVER MAINE WHILE HIPRES CONTINUES TO BUILD INTO THE AREA ON THU. THE PRESSURE GRADIENT WILL NOT BE AS STRONG THU AS TDA...BUT NW WINDS WILL GUST AROUND 20 TO 25 MPH IN THE AFTN. DESPITE PLENTY OF SUNSHINE...TEMPS WILL STRUGGLE TO REACH THE 80 DEGREE MARK. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... THURSDAY NIGHT THROUGH FRIDAY NIGHT...AN A UPPER LOW PERSISTS ACROSS NEW ENGLAND AS A RIDGE AMPLIFIES AS IT DRIFTS EAST ACROSS THE MIDWEST. THIS PATTERN WILL MAINTAIN DRY NWLY FLOW WITH SUNNY/CLEAR CONDITIONS WITH MAX TEMPS LIMITED TO THE MID TO UPR 70S /AROUND FIVE DEGREES BELOW NORMAL/. MIN TEMPS A FEW DEGREES BELOW NORMAL BOTH NIGHTS...GENERALLY LOW TO MID 50S INLAND...UPR 50S FOR URBAN AREAS. SATURDAY...THE RIDGE AXIS BEGINS TO CROSS THE CWA WITH HIGH/MID CLOUDS SPREADING EAST. WARMER LOW LEVEL AIR SPREADS EAST WITH THE RIDGE...SO SHOULD NOT MANY OVERRUNNING CLOUDS BE PRESENT...MAX TEMPS SHOULD REACH THE LOW 80S EAST OF THE BLUE RIDGE /AND AROUND 80F ALONG WEST/. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT ASSOCIATED WITH A LOW OVER NRN ONTARIO LOOKS TO CROSS THE MID ATLANTIC LATER SUNDAY. INSTABILITY IN THE WARM SECTOR SHOULD ENABLE PREFRONTAL ACTIVITY THAT WOULD ENTER THE WRN ZONES EARLY SAT NIGHT...WHICH DEPENDING ON ORGANIZATION MAY REACH EAST OF THE BLUE RIDGE BEFORE DAYBREAK. WENT WITH HIGH CHANCE POPS LATE SATURDAY NIGHT OUT WEST...MID CHANCE /40 PERCENT/ EAST FOR SUNDAY. AFTER THE COLD FROPA SFC HIGH PRESSURE BRIEFLY BUILDS MONDAY BEFORE ANOTHER TROUGH CROSSES THE NERN CONUS...BRINGING A MAINLY DRY COLD FRONT IN THE TUESDAY TIMEFRAME. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS TNGT AND THU. SUSTAINED W-NW WINDS AROUND 15-20 KT WITH GUSTS TO 25 KT WILL CONTINUE THRU THE LATE AFTN BEFORE RELAXING AROUND SUNSET. NW WINDS WILL INCREASE ONCE AGAIN AFTER SUNRISE THU MRNG WITH GUSTS TO 20 KT POSSIBLE. NWLY FLOW WITH VFR CONDS CONTINUES THUR NIGHT INTO THE WEEKEND. NEXT COLD FRONT AFFECTS THE AREA LATE SAT NIGHT THROUGH SUNDAY. HIGH PRESSURE BUILDS SUNDAY NIGHT AND MONDAY. && .MARINE... WIDESPREAD SCA CONDITIONS WITH W-NW GUSTS 20-25 KT THRU THE REST OF THE AFTN. SCA CONDITIONS SHOULD CONTINUE ACROSS THE LOWER TIDAL POTOMAC AND CHSPK BAY INTO TNGT BEFORE NW WINDS REACH SCA CRITERIA ACROSS ALL MARINE ZONES DURING THE DAY THU. LEFT SCA OUT OF THURSDAY NIGHT ATTM...THOUGH AN UPPER LOW OVER NEW ENGLAND WILL MAINTAIN A PRESSURE GRADIENT FOR NWLY FLOW ACROSS THE BAY THROUGH FRIDAY. HIGH PRESSURE RIDGE CROSSES ON SATURDAY WITH RETURN SLY FLOW STARTING LATE SATURDAY. THE NEXT COLD FRONT CROSSES THE BAY LATE SUNDAY...THOUGH PREFRONTAL SHOWERS AND STORMS COULD START EARLY SUNDAY. && .FIRE WEATHER... ***GOV OF W.V. HAS ISSUED A BURNING BAN FOR ERN WV PANHANDLE WHICH WILL CONTINUE UNTIL FURTHER NOTICE.*** EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE...GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. RED FLAG WRNG CONTINUES THRU 7 PM FOR MOST OF THE AREA WITH THE EXCEPTION OF THE NRN PIEDMONT AND LOWER SRN MD /WHERE THE PRESSURE GRADIENT AND WINDS REMAIN WEAKER/. WINDS SHOULD RELAX AND RH VALUES WILL INCREASE TOWARD SUNSET. TIGHT PRESSURE GRADIENT WILL CONTINUE INTO THU AND FRI. WHILE NW WINDS /AROUND 10 TO 15 MPH/ ARE EXPECTED TO BE JUST BELOW RED FLAG WRNG CRITERIA ATTM...GUSTY WINDS AROUND 20 TO 25 MPH WILL KEEP AN ENHANCED FIRE WX THREAT DURING THE AFTERNOONS EACH DAY. WILL COORDINATE WITH FIRE OFFICIALS...BUT FEEL THAT AT LEAST AN SPS MENTIONING THE HEIGHTENED THREAT WILL BE NEEDED BOTH DAYS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR DCZ001. MD...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MDZ003>007- 009>011-013-014-501-502. VA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VAZ021- 025>031-038>040-042-051>054-501-502. WV...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR WVZ050>055- 501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>534- 537-539>541-543. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535- 536-538-542. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ535- 536-538-542. && $$ SYNOPSIS...BAJ NEAR TERM...JRK SHORT TERM...BAJ LONG TERM...BAJ AVIATION...BAJ/JRK MARINE...BAJ/JRK FIRE WEATHER...JRK 000 FXUS61 KAKQ 081852 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 252 PM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH OF THE REGION THROUGH TONIGHT. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST ON SATURDAY... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... A RELATIVELY DRY COLD FRONT IS MAKING ITS WAY ACROSS THE REGION THIS AFTERNOON. THE FRONT HAS TRIGGERED SOME ISOLATED SHWR ACTIVITY ACROSS OUR SW ZONES...BUT NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION AS THESE SHWRS SLOWLY DIE OUT AND DRIFT SOUTH THROUGH THE EVENING. THERE IS A VERY DISTINCT BACK EDGE TO THE CLOUD DECK NOTED ON CURRENT VISIBLE SATELLITE PICS. THE BACK EDGE WILL PUSH SOUTH OF THE RICHMOND METRO BY MID-AFTERNOON...AND AS THE FRONT CONTINUES TO DRIFT SOUTH...THE CLOUDS SHOULD MOVE OUT OF OUR CWA AROUND OR JUST AFTER SUNSET SETTING THE STAGE FOR A CLEAR SKY TONIGHT. A NOTICEABLE DROP IN DEW POINTS (MID-40S TO MID-50S) IS NOTED OVER THE MD/WV PANHANDLES AND NORTHERN VA THIS AFTERNOON... AND THIS DRIER AIR WILL CONTINUE TO WORK SOUTHWARD INTO OUR AREA TONIGHT. WITH A CLEAR SKY...LIGHT WINDS AND DRIER AIR IN PLACE TONIGHT...EXPECTING PLEASANT CONDITIONS. LOWS WILL FALL INTO THE 50S TO NEAR 60 INLAND WITH MID/UPR 60S NEAR THE COAST. WINDS WILL DIMINISH AROUND SUNSET. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH AN UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE MID/UPR 70S ACROSS THE NORTH TO LOW/MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. AFTERNOON DEW POINTS WILL DROP INTO THE 40S AND LOW 50S BOTH DAYS...YIELDING COMFORTABLE HUMIDITY LEVELS. SURFACE HIGH PRESSURE WILL LIKELY REMAIN OVER THE REGION FOR DRY WEATHER AGAIN ON SATURDAY. HOWEVER...THE NEXT SYSTEM WILL LIKELY BRING SOME CLOUDS TO THE AREA LATE IN THE DAY. MODELS KEEP PRECIP WEST OF OUR AREA THROUGH SATURDAY AFTERNOON...SO WILL CONTINUE WITH A DRY FORECAST FOR NOW. HIGH TEMPS WILL BE IN THE LOW/MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... STILL GETTING 17-18 KT WAVES IN THE MIDDLE AND SRN BAY SO DECIDED TO EXTEND SCA UNTIL 2 PM. EXPECT WNDS TO DECREASE OVER THE WTRS THRU THE AFTERNOON AS LAND AREAS HEAT UP. ANOTHER SCA MIGHT HAVE TO BE RAISED LATER THIS EVENING OR TONIGHT AFTER FRONTAL BNDRY MOVES THRU THE WTRS. WNDS WILL THEN SHIFT TO NW-N OVERNIGHT INTO EARLY MORNING AND BRIEF SURGE BEHND TO FRONT MAY RAISE WNDS AND SEAS TO SCA FOR A SHORT PERIOD OF TIME. OTW HI PRES WILL GRADUALLY MOVE INTO THE REGION ON THU AND CONT DRY WX. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .FIRE WEATHER... WILL CONTINUE WITH A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER ACROSS OUR NORTHERN COUNTIES IN VA AND INTO THE LOWER MD EASTERN SHORE THROUGH 7PM. RH VALUES DROPPING INTO THE 30S WITH CLEAR SKIES AND WIND GUSTS TO 25 MPH WILL ENHANCE THE THREAT FOR WILDFIRES IN THESE AREAS TIL 7PM. AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER ON THURSDAY... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS EXPECTED...WILL AGAIN HIGHLIGHT THE THREAT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON IN A SPECIAL WEATHER STATEMENT. THIS STATEMENT WILL INCLUDE ALL OF OUR COUNTIES IN VA EXCEPT SE VA AND THE LOWER EASTERN SHORE. IT WILL ALSO INCLUDE THE LOWER MD EASTERN SHORE. AN ADDITIONAL STATEMENT MAY BE NECESSARY FOR FRIDAY AS CONDITIONS ARE EXPECTED TO BE SIMILAR TO THURSDAY. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ631- 632. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...JDM LONG TERM...AJZ AVIATION...JEF MARINE...AJZ FIRE WEATHER...JDM 000 FXUS61 KPBZ 081835 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 235 PM EDT WED SEP 8 2010 .SYNOPSIS... NORTHWEST WINDS ALOFT WILL BRING COOL CONDITIONS THROUGH FRIDAY WITH THE NEXT CHANCE OF SIGNIFICANT RAIN LATE SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... STRATOCU HAS REACHED TO JUST NORTH OF KPIT THIS AFTERNOON AND BULK OF THIS WILL DISSIPATE THIS EVENING EXCEPT ACROSS THE FAR NORTH WHERE FLOW OFF THE LAKES WILL KEEP SOME CLOUDS IN OVERNIGHT. NORTHWEST FLOW WILL CONTINUE ACROSS REGION INTO THURSDAY AS UPPER LEVEL LOW WOBBLES ACROSS NEW ENGLAND . TEMPERATURES CLOSE TO MODEL MOS. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... SHORTWAVE WILL PIVOT ON THE BACKSIDE OF UPPER LOW THURSDAY NIGHT WITH SOME CLOUDS MAINLY NORTH AND POSSIBLE SPRINKLE. UPPER LOW THEN EXITS FRIDAY WITH RIDGE IN CONTROL UNTIL LATE SATURDAY. ON SATURDAY A WARM FRONT AHEAD OF AN UPPER TROUGH FROM THE PLAINS WILL INCREASE CLOUDS AND BRING WARMER TEMPERATURES. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NEARLY OCCLUDED WARM FRONT WILL PUSH ACROSS REGION SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SHOWERS. SHOWERS WILL DIMINISH BY SUNDAY AFTERNOON WITH HIGH PRESSURE BRINGING A DRY MONDAY. WEAK COLD FRONT WILL BRING JUST A SLIGHT CHANCE FOR SHOWERS TUESDAY INTO WEDNESDAY WITH SEASONABLE TEMPERATURES. GENERALLY IN AGREEMENT WITH SPC PROGS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... NW FLOW INCREASING...WITH STRATOCUMULUS DECK ALONG AND NORTH OF I80. WILL GRADUALLY SINK A LITTLE FARTHER SOUTH BY EVENING. LOWER EDGE SHOULD SCATTER OUR AFTER AS SUN LOWERS, BUT BKN DECK LIKELY ACROSS THE NORTH FOR FIRST HALF OF NIGHT. REMAINING SC DECK WILL GRADUALLY ERODE TNGT AS HIGH PRESSURE BEGINS TO BUILD IN. VFR WILL PREVAIL FOR THURSDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KAKQ 081826 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 226 PM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THROUGH THIS EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... WATCHING A DRY COLD FRONT MOVE INTO THE AREA THIS MORNING. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THE FRONT. STILL HAVE ISOLATED SHWRS POSSIBLE OVER NE NC THIS AFTERNOON. THE FRONT IS GENERATING QUITE A BIT OF CLOUD COVER...SO HAVE INCREASED CLOUDS FOR THE REMAINDER OF THE DAY TO PARTLY TO MOSTLY CLOUDY. THESE CLOUDS SHOULD INHIBIT TEMPS FORM REACHING THEIR FULLEST POTENTIAL THIS AFTERNOON. AS SUCH HAVE TRIMMED EXPECTED HIGH TEMPS BY A COUPLE OF DEGREES. THE OTHER CONCERN IS AN INCREASED FIRE WX RISK FOR THIS AFTERNOON AS DRIER AIR ARRIVES BEHIND THE FRONT. PLEASE SEE FIRE WX SECTION BELOW FOR MORE INFO. PREVIOUS DISCUSSION BELOW... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... RADAR SHOWING AREA OF LIGHT TO OCNL MOD RAINSHOWERS OVER THE SOUTHERN PORTIONS OF OUR REGION MOVG TO THE SE. SOME ISOLD SHOWERS MY OCCUR OVER PARTS OF CENTRL VA AND COULD AFFECT RIC THIS AFTERNOON. HOWEVER DO NOT EXPECT TO SEE OTHER THAN VFR CONDS. FRONTL BNDRY WILL PUSH THRU THE REGION THIS EVENING/TONIGHT AND WNDS WILL SHFT FROM W-NW-N INTO EARLY THU MRNG. HI PRES BUILDS INTO THE REGION ON THU AND TEMPS WILL BE A LITTLE COOLER. VFR CONDS INTO THE WEEKEND. ANOTHER COLD FRNT APPROACHES ON SUN. && .MARINE... STILL GETTING 17-18 KT WAVES IN THE MIDDLE AND SRN BAY SO DECIDED TO EXTEND SCA UNTIL 2 PM. EXPECT WNDS TO DECREASE OVER THE WTRS THRU THE AFTERNOON AS LAND AREAS HEAT UP. ANOTHER SCA MIGHT HAVE TO BE RAISED LATER THIS EVENING OR TONIGHT AFTER FRONTAL BNDRY MOVES THRU THE WTRS. WNDS WILL THEN SHIFT TO NW-N OVERNIGHT INTO EARLY MORNING AND BRIEF SURGE BEHND TO FRONT MAY RAISE WNDS AND SEAS TO SCA FOR A SHORT PERIOD OF TIME. OTW HI PRES WILL GRADUALLY MOVE INTO THE REGION ON THU AND CONT DRY WX. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .FIRE WEATHER... AFTER COORDINATING WITH FIRE AGENCIES IN BOTH VA AND MD...WILL BE ISSUING A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER THIS AFTERNOON ACROSS OUR NORTHERN COUNTIES INTO THE LOWER MD EASTERN SHORE. DRIER AIR MOVING IN BEHIND A PASSING SURFACE COLD FRONT WILL ALLOW MINIMUM RH VALUES TO FALL INTO THE 30-40% RANGE BETWEEN 3PM-6PM THIS AFTERNOON/EVENING. WINDS ALSO ALSO BE IN THE 10-15 MPH RANGE WITH GUSTS BETWEEN 20-25 MPH. THESE CONDITIONS IN COMBINATION WITH 10 HR FUELS AOB 10% WILL ENHANCE THE THREAT FOR WILDFIRES IN THESE AREAS. AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER ON THURSDAY... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS IN PLACE WILL PROBABLY NEED A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON AS WELL IN VA AND MD. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...JDM LONG TERM...AJZ AVIATION...JEF MARINE...AJZ/JEF FIRE WEATHER... 000 FXUS61 KPHI 081800 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 200 PM EDT WED SEP 8 2010 .SYNOPSIS... THE COLD FRONT WILL MOVE OFF TO THE EAST THIS AFTERNOON AS LOW PRESSURE CROSSES NORTHERN NEW ENGLAND. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA THROUGH FRIDAY. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY. ANOTHER HIGH PRESSURE SYSTEM WILL BUILD IN FOR MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... TEMPERATURES ARE RISING ABOVE THE FORECAST HIGHS IN MANY AREA THIS AFTERNOON AS DRY AIR STREAMS IN FROM THE WEST. ALL GRIDS AND FORECASTS HAVE BEEN UPDATED ACCORDINGLY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AN AREA OF LOW PRESSURE IS FORECAST TO BE NEAR NORTHERN NEW ENGLAND AS A CLOSED MIDLEVEL LOW SETS UP SHOP IN THAT VICINITY. THE ASSOCIATED LARGE TROUGH ENCOMPASSING THE NORTHEAST AND MID ATLANTIC STATES WILL RESULT IN A CYCLONIC FLOW BRINGING COOLER AIR TO THE REGION. THE NORTHWESTERLY FLOW OF THIS COOL AND DRY AIRMASS WILL ALLOW FOR LITTLE CLOUDS TO OCCUR TONIGHT. THE EXCEPTION SHOULD BE THE NORTHWESTERN ZONES WHERE THE CAA, COMBINED WITH THE FLOW OFF THE WARM EASTERN GREAT LAKES, CYCLONIC FLOW AND MOISTURE BECOMING TRAPPED UNDER AN INVERSION TO TOSS STRATOCUMULUS SOUTHEASTWARD. THEREFORE WE WILL CARRY MORE CLOUDS THERE THROUGH THE NIGHT AND ALSO DURING THURSDAY. THE WIND TONIGHT SHOULD DECOUPLE AT LEAST SOME, ALTHOUGH A COMPLETE DECOUPLING IS NOT ANTICIPATED GIVEN THE TIGHTENED PRESSURE GRADIENT AND CAA. THEREFORE, WE WILL GRADUALLY THROTTLE BACK ON THE WINDS. A FEW SHOWERS/SPRINKLES CANNOT BE RULED OUT MAINLY THURSDAY AFTERNOON THROUGH FRIDAY, THEREFORE SLIGHT CHC POPS WILL BE MAINTAINED AT TIMES FOR THE NORTHWESTERN ZONES. WE ARE SEEING A LITTLE INSTABILITY IN THE FORECAST SOUNDINGS THURSDAY AFTERNOON FARTHER SOUTH, THEREFORE CAA STRATOCUMULUS/CUMULUS WILL PROBABLY DEVELOP BUT POTENTIALLY FIGHT THE DOWNSLOPING FLOW /AS OF NOW WE ARE NOT ANTICIPATING ANY SPRINKLES OR BRIEF SHOWERS TO BE ABLE TO DEVELOP FROM THIS/. WE TRIED TO INDICATE THIS IN THE SKY COVER GRIDS FROM NORTHWEST TO SOUTHEAST. FOR FRIDAY, THE PRESSURE GRADIENT IS FORECAST TO GRADUALLY RELAX THEREFORE THE WINDS SHOULD NOT BE AS GUSTY COMPARED TO TODAY AND THURSDAY. AS FOR TEMPERATURES, WE GENERALLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE NAM/GFS MOS BUT MADE A FEW ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THIS TIME FRAME IS COMPRISED OF SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, LOW TEMPERATURES MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE HAVE SHOWERS AND THUNDERSTORMS CHCS ARRIVING DURING THE DAY ON SUNDAY. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WITH RESPECT TO THUNDER WITH THE GFS MORE BULLISH OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PRECIPITATION EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE MODEL RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHOWER SLIGHT CHC/CHC WERE ADDED ATTM. TEMPERATURE-WISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH READINGS PRETTY CLOSE TO AVERAGE. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE COLD FRONT IS SLOWER IN ARRIVING. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 15Z-00Z...VFR WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... THURSDAY AND FRIDAY: VFR. GUSTY WNW WINDS 20-28 KTS DAYLIGHT HOURS DIMINISH AT NIGHT. CYCLONIC FLOW DOMINATES OUR WEATHER THROUGH FRIDAY WITH A SECONDARY WEAK COOL FRONTAL PASSAGE THURSDAY AFTERNOON OR EVENING. DIURNALLY HEAT DRIVEN CONSIDERABLE CLOUD COVER 3500 TO 5500 FT THURSDAY AND FRIDAY DAYLIGHT HOURS TENDS TO CLEAR AT NIGHT. MOST OF THE CLOUDINESS EASTERN PA AND NORTHERN TWO THIRDS OF NJ. SCT SHOWERS OR SPRINKLES POSSIBLE THURSDAY AFTERNOON POCONOS AND NORTHERN NJ WITH SHORT WAVE ROTATING SEWD THRU THE AREA AND A WEAK WIND SHIFT. SATURDAY...VFR LIGHT WIND AND HIGH PRESSURE OVERHEAD. SUNDAY...CONDITIONS MAY DEGRADE IN POTENTIAL LOW PRESSURE PASSAGE WITH MVFR CONDS IN SHOWERS. && .MARINE... TODAY...SCA THROUGH 00Z THU FOR NEARSHORE WATERS WITH GUSTS UP TO AROUND 25 KTS. SEAS 3 TO 5 FT ON THE OCEAN AND 2 TO 4 FEET IN THE BAY. TONIGHT...WINDS MAY CONTINUE OCCASIONALLY GUSTING 25 KTS VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD FROM THE COAST. THE EXCEPTION FOR TONIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY AND FRIDAY...NW WIND GUSTS 20-25 KNOTS. MIGHT BE A SECONDARY WEAK CFP LATE IN THE DAY THAT ENHANCES WIND TRANSFER INTO THU NIGHT. SATURDAY...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS. SUNDAY...DEGRADING CONDITIONS IN POTENTIAL SHOWERS AND LOW PRESSURE. && .FIRE WEATHER... FOLLOWING THE PASSAGE OF THE COLD FRONT THIS MORNING, MUCH DRIER AIR AND INCREASING WINDS WILL ARRIVE ACROSS THE AREA. THIS WILL ALLOW THE DEW POINTS TO TUMBLE AS WINDS INCREASE FROM THE WEST. MODEL FORECAST SOUNDINGS SUGGEST MIXING FROM 850 MB COULD DROP DEW POINTS INTO THE MID AND UPPER 40S THIS AFTERNOON. MODEL FORECAST SOUNDINGS ALSO SHOW THAT ABOUT 30 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE DEEPENING BOUNDARY LAYER THIS AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS OF 30 TO 35 MPH, MAINLY FROM LATE MORNING ON. GIVEN THE RATHER DRY CONDITIONS ACROSS THE REGION AND FORECAST WINDS AND RELATIVE HUMIDITY VALUES, THE START TIME FOR THE RED FLAG WARNING HAS BEEN MOVED UP TO NOON TODAY. WE ARE ANTICIPATING GUSTY WINDS ON THURSDAY, HOWEVER WITH COOLER TEMPERATURES THE RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER RELATED HEADLINES. A MENTION WILL BE INCLUDED ONLY IN THE FIRE WEATHER FORECAST FOR NOW. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ TODAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE THIS IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR PAZ060-061- 067>071. NJ...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NJZ009-010- 012>027. DE...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MDZ008-012- 015. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE/RPW NEAR TERM...DRAG/GORSE/RPW SHORT TERM...SHORT LONG TERM...GIGI/GORSE AVIATION...DRAG/KRUZDLO MARINE...DRAG/DRUZDLO FIRE WEATHER...HAYES/GORSE/RPW CLIMATE...637A 000 FXUS61 KLWX 081533 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC ISSUED BY NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1133 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT WAS MOVING INTO THE CHESAPEAKE BAY AREA LATE THIS MORNING. IT WILL BRING DRIER AND BREEZY CONDITIONS. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND PERSIST INTO THE WEEKEND. ANOTHER COLD FRONT WILL IMPACT THE REGION SUNDAY, WHICH WILL BE FOLLOWED BY MORE HIGH PRESSURE. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHOWERS HAD CLEARED ALL BUT THE FAR SOUTHERN PART OF THE AREA THIS MORINING, AND THEY SHOULD CLEAR THE LOCATIONS SOUTH OF CHO SHORTLY. THE ADVERTISED DROP IN DEW POINTS AND INCREASE IN WESTERLY WINDS WAS UNDERWAY BEHIND THE FRONT, AND SOME COMPRESSIONAL HEATING SEEMED TO BE OCCURRING IN RESPONSE. TEMPERATURES AT SEVERAL LOCATIONS AROUND THE AREA WERE NUDGED UP JUST A LITTLE. THIS IS CONSISTENT WITH THE OBSERVATION BY THE PREVIOUS FORECASTER THAT GUIDANCE HAS BEEN RUNNING ON THE COOL SIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... TNGT THINGS WL SETTLE DOWN AS HIGH PRES BLDS INTO THE RGN. CLR SKIES. WINDS SHOULD DECOUPLE AFTR MDNGT AS LO LVL INVRSN FORMS. IN SPITE OF THE POST FRONTAL CAA ENVIRONMENT I HV LOW TEMPS FAIRLY CLOSE TO CLIMO NORMS FOR THE 2ND WK OF SEP...RANGING FM MU40S IN THE HIGHLANDS...50S MUCH OF THE AREA...LM60S IN CITIES/ALONG THE BAY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... TROF-RIDGE-TROF FOR THE CONUS FOR THE SECOND-HALF OF THE WEEK. THE FIRST TROF WILL BE SLOWLY DRIFTING OVER THE ST LAWRENCE CHANNEL THU/FRI. THE FURTHER EAST THIS FEATURE MOVES...THE WARMER AND LESS WINDY THE MID ATLC WILL BE. CONSEQUENTLY...THE BREEZY CONDITIONS THAT WE/LL SEE TODAY POST-FRONTAL WILL BE SUBSIDING A BIT EACH AFTN...THOUGH THE END OF THE WEEK. NEXT...THE REMNANTS OF HERMINE WILL DRIFT INTO THE MID MS VLY ON FRI...EMBEDDED IN THE WEAK UPPER RIDGE OVER THE CNTRL PLAINS. THE REMNANT LOW WILL BE ABSORBED INTO ANOTHER APPROACHING UPPER TROF /THE SECOND TROF FEATURE/ THAT WILL BE STRENGTHENING OVER THE NRN ROCKIES/PLAINS - MUCH LIKE THE FIRST LOW PRESSURE SYSTEM HAS DONE OVER THE PAST COUPLE OF DAYS. A STRONG ZONAL PATTERN OVER MUCH OF THE COUNTRY /OR A WEAK BUT LARGE AND ELONGATED RIDGE OVER THE SRN HALF OF THE CONUS/ WILL SETTLE IN BY SUNDAY. THIS SCENARIO LOOKS LIKE IT WILL BE THE STORY FOR MUCH OF NEXT WEEK. THE ONLY FEATURES AFFECTING THE REGION DURING THIS PERIOD WOULD BE ON SUNDAY...AS THE SECOND TROF SLIDES ACROSS THE ERN SEABOARD AND PUSHES A WEAK COLD FRONT ACROSS THE MID ATLC. THE OTHER FEATURE WOULD BE ANOTHER WEAK UPPER SHORT WAVE SWINGING DOWN FROM THE GREAT LAKES REGION TUE INTO WED OF NEXT WEEK. TEMPS/DEWPOINTS WILL BECOME MORE STEADILY SEASONABLE DURING THIS LONG RANGE PERIOD. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS TDA/TNGT. XPCT WINDS TO SHIFT TO THE W ARND NOON AND BECOME GUSTY THIS AFTN. CLR SKIES AND LGT WINDS AFTR 00Z. VFR CONDITIONS FOR THE LONG RANGE. A COLD FRONT WILL MOVE THROUGH ON SUNDAY...BRINGING THE BEST CHANCE FOR SCATTERED SHOWERS /AND A LOW CHANCE AT THAT/. WINDS WOULD BE THE MAIN CONCERN W/ 15-20KT GUSTS POSSIBLE THU AND FRI AFTN. && .MARINE... SCA CURRENTLY IN EFFECT AND WL RMN SO THRU THE DAY AND EVE HRS ACROSS ALL THE WATERS. GIVEN CAA OVR XTRMLY WARM WATERS WINDS WL CONTINUE TO BE GUSTY OVR THE BAY AND LOWER PTMC OVRNGT. INCREASING WINDS DURING EACH AFTN FOR THE NEXT FEW DAYS...MAINLY THU AND FRI FOR THE LONG RANGE FORECAST. NWLY FLOW WILL INCREASE DURING THE MID MORNING HRS EACH DAY AND PEAK LATE AFTN/EVE...FOR MORE LIKELY CONTINUED SCA CONDITIONS THROUGH THE END OF THE WORK WEEK. WINDS SHOULD DECREASE FOR WEEKEND AS HIGH PRESSURE BRIEFLY MOVES LATE FRI/SAT...BUT THEN ANOTHER COLD FRONT MOVES THROUGH ON SUNDAY. && .FIRE WEATHER... ***GOV OF W.V. HAS ISSUED A BURNING BAN FOR ERN WV PANHANDLE WHICH WILL CONTINUE UNTIL FURTHER NOTICE.*** EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE, GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. A COLD FRONT WAS MOVING THROUGH THE REGION ON A SIGNIFICANT BREEZE. IT WAS BRINGING LOW RH VALUES WITH IT. A RED FLAG WARNING HAS BEEN ISSUED FOR ALL BUT THE SOUTHERN TIER, WHERE WE HAVE ISSUED A SPS FOR ENHANCED FIRE WEATHER CONCERNS. NWLY FLOW WILL CONTINUE FOR THURSDAY AND FRIDAY, MAINTAINING AN ENHANCED FIRE WX THREAT. && .TIDES/COASTAL FLOODING... THE THREAT OF COASTAL FLOODING SEEMED TO HAVE PASSED, AND THE ADVISORY HAS BEEN DROPPED. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR DCZ001. MD...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MDZ003>007- 009>011-013-014-501-502. VA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VAZ021- 025>031-038>040-042-051>054-501-502. WV...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR WVZ050>055- 501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>534- 537-539>541-543. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535- 536-538-542. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ535- 536-538-542. && $$ PRODUCTS...WOODY!/GMS/MPD 000 FXUS61 KAKQ 081515 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1115 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THROUGH THIS EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATCHING A DRY COLD FRONT MOVE INTO THE AREA THIS MORNING. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THE FRONT. STILL HAVE ISOLATED SHWRS POSSIBLE OVER NE NC THIS AFTERNOON. THE FRONT IS GENERATING QUITE A BIT OF CLOUD COVER...SO HAVE INCREASED CLOUDS FOR THE REMAINDER OF THE DAY TO PARTLY TO MOSTLY CLOUDY. THESE CLOUDS SHOULD INHIBIT TEMPS FORM REACHING THEIR FULLEST POTENTIAL THIS AFTERNOON. AS SUCH HAVE TRIMMED EXPECTED HIGH TEMPS BY A COUPLE OF DEGREES. THE OTHER CONCERN IS AN INCREASED FIRE WX RISK FOR THIS AFTERNOON AS DRIER AIR ARRIVES BEHIND THE FRONT. PLEASE SEE FIRE WX SECTION BELOW FOR MORE INFO. PREVIOUS DISCUSSION BELOW... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... STILL GETTING 17-18 KT WAVES IN THE MIDDLE AND SRN BAY SO DECIDED TO EXTEND SCA UNTIL 2 PM. EXPECT WNDS TO DECREASE OVER THE WTRS THRU THE AFTERNOON AS LAND AREAS HEAT UP. ANOTHER SCA MIGHT HAVE TO BE RAISED LATER THIS EVENING OR TONIGHT AFTER FRONTAL BNDRY MOVES THRU THE WTRS. WNDS WILL THEN SHIFT TO NW-N OVERNIGHT INTO EARLY MORNING AND BRIEF SURGE BEHND TO FRONT MAY RAISE WNDS AND SEAS TO SCA FOR A SHORT PERIOD OF TIME. OTW HI PRES WILL GRADUALLY MOVE INTO THE REGION ON THU AND CONT DRY WX. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .FIRE WEATHER... AFTER COORDINATING WITH FIRE AGENCIES IN BOTH VA AND MD...WILL BE ISSUING A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER THIS AFTERNOON ACROSS OUR NORTHERN COUNTIES INTO THE LOWER MD EASTERN SHORE. DRIER AIR MOVING IN BEHIND A PASSING SURFACE COLD FRONT WILL ALLOW MINIMUM RH VALUES TO FALL INTO THE 30-40% RANGE BETWEEN 3PM-6PM THIS AFTERNOON/EVENING. WINDS ALSO ALSO BE IN THE 10-15 MPH RANGE WITH GUSTS BETWEEN 20-25 MPH. THESE CONDITIONS IN COMBINATION WITH 10 HR FUELS AOB 10% WILL ENHANCE THE THREAT FOR WILDFIRES IN THESE AREAS. AFTERNOON RELATIVE HUMIDITIES WILL LOWER FURTHER ON THURSDAY... REACHING THE 20-25% RANGE ACROSS THE WESTERN HALF OF OUR CWA...WITH FUEL MOISTURE REMAINING LOW AS WELL. HOWEVER...WINDS WILL BE SOMEWHAT LOWER. WITH THESE DRY CONDITIONS IN PLACE WILL PROBABLY NEED A SPECIAL WEATHER STATEMENT FOR INCREASED FIRE DANGER THURSDAY AFTERNOON AS WELL IN VA AND MD. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ631- 632. && $$ SYNOPSIS...BKH NEAR TERM...BKH/JDM SHORT TERM...BKH LONG TERM...LKB AVIATION...TMG MARINE...JEF FIRE WEATHER... 000 FXUS61 KPHI 081506 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1106 AM EDT WED SEP 8 2010 .SYNOPSIS... THE COLD FRONT WILL MOVE OFF TO THE EAST THIS AFTERNOON AS LOW PRESSURE CROSSES NORTHERN NEW ENGLAND. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA THROUGH FRIDAY. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE SATURDAY. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY. ANOTHER HIGH PRESSURE SYSTEM WILL BUILD IN FOR MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE COLD FRONT WILL MOVE OFF THE MID ATLANTIC COAST EARLY THIS AFTERNOON. THE THREAT OF SHOWERS HAS ALL BUT ENDED, SO WE HAVE TAKEN ALL MENTION OF PRECIPITATION OUT OF THE GRIDS FOR TODAY. THE REMAINDER OF THE FORECAST LOOKS GOOD AS THE DRY AIR PUSHES IN AND WINDS INCREASE. SYNOPTICALLY, A STRONG UPPER-LEVEL TROUGH WILL BE MIGRATING FROM THE GREAT LAKES REGION TO THE NORTHEAST THROUGH TODAY. THE CYCLONIC FLOW BEHIND THE SURFACE COLD FRONT WILL ALLOW FOR INCREASING CAA WITH TIME. MID TO HIGH LEVEL CLOUDS ALONG AND AHEAD OF THE COLD FRONT HAVE ALREADY DISAPPEARED. THIS WILL LEAVE MOSTLY SUNNY SKIES FOR THE REMAINDER OF THE DAY. GUSTY WINDS WILL DEVELOP BEHIND THE COLD FRONT AS THE LOW-LEVEL LAPSE RATES STEEPEN WITH THE DEVELOPING CAA ABOVE SURFACE HEATING. THE FORECAST SOUNDINGS INDICATE THAT THE WINDS INCREASE TO NEARLY 30 KNOTS AT THE TOP OF THE DEEPENING BOUNDARY LAYER. THIS WOULD TRANSLATE TO 30 TO 35 MPH WIND GUSTS BEHIND THE FRONT. THIS WILL PROBABLY BE DELAYED SLIGHTLY ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES AS THE COLDER AIR TAKES A WHILE TO WORK ITS WAY IN. OVERALL, THE SITUATION LOOKS TO BE BELOW WIND ADVISORY CRITERIA. THE WINDS COMBINED WITH THE DRIER AIR SURGING IN BEHIND THE FRONT WILL LEAD TO FIRE WEATHER CONCERNS, THEREFORE SEE THE FIRE WEATHER SECTION BELOW FOR MORE DETAILS. AS FOR TEMPERATURES, GIVEN THE MILD START ACROSS THE BULK OF THE CWA UNDER WAA AHEAD OF THE COLD FRONT, LEANED TOWARD THE WARMER NAM MOS. THIS POINTS TOWARD WARMER TEMPERATURES ESPECIALLY ACROSS THE EASTERN AND SOUTHERN ZONES AS THE CAA WILL ARRIVE HERE IN EARNEST LATER IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN AREA OF LOW PRESSURE IS FORECAST TO BE NEAR NORTHERN NEW ENGLAND AS A CLOSED MIDLEVEL LOW SETS UP SHOP IN THAT VICINITY. THE ASSOCIATED LARGE TROUGH ENCOMPASSING THE NORTHEAST AND MID ATLANTIC STATES WILL RESULT IN A CYCLONIC FLOW BRINGING COOLER AIR TO THE REGION. THE NORTHWESTERLY FLOW OF THIS COOL AND DRY AIRMASS WILL ALLOW FOR LITTLE CLOUDS TO OCCUR TONIGHT. THE EXCEPTION SHOULD BE THE NORTHWESTERN ZONES WHERE THE CAA, COMBINED WITH THE FLOW OFF THE WARM EASTERN GREAT LAKES, CYCLONIC FLOW AND MOISTURE BECOMING TRAPPED UNDER AN INVERSION TO TOSS STRATOCUMULUS SOUTHEASTWARD. THEREFORE WE WILL CARRY MORE CLOUDS THERE THROUGH THE NIGHT AND ALSO DURING THURSDAY. THE WIND TONIGHT SHOULD DECOUPLE AT LEAST SOME, ALTHOUGH A COMPLETE DECOUPLING IS NOT ANTICIPATED GIVEN THE TIGHTENED PRESSURE GRADIENT AND CAA. THEREFORE, WE WILL GRADUALLY THROTTLE BACK ON THE WINDS. A FEW SHOWERS/SPRINKLES CANNOT BE RULED OUT MAINLY THURSDAY AFTERNOON THROUGH FRIDAY, THEREFORE SLIGHT CHC POPS WILL BE MAINTAINED AT TIMES FOR THE NORTHWESTERN ZONES. WE ARE SEEING A LITTLE INSTABILITY IN THE FORECAST SOUNDINGS THURSDAY AFTERNOON FARTHER SOUTH, THEREFORE CAA STRATOCUMULUS/CUMULUS WILL PROBABLY DEVELOP BUT POTENTIALLY FIGHT THE DOWNSLOPING FLOW /AS OF NOW WE ARE NOT ANTICIPATING ANY SPRINKLES OR BRIEF SHOWERS TO BE ABLE TO DEVELOP FROM THIS/. WE TRIED TO INDICATE THIS IN THE SKY COVER GRIDS FROM NORTHWEST TO SOUTHEAST. FOR FRIDAY, THE PRESSURE GRADIENT IS FORECAST TO GRADUALLY RELAX THEREFORE THE WINDS SHOULD NOT BE AS GUSTY COMPARED TO TODAY AND THURSDAY. AS FOR TEMPERATURES, WE GENERALLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE NAM/GFS MOS BUT MADE A FEW ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THIS TIME FRAME IS COMPRISED OF SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, LOW TEMPERATURES MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE HAVE SHOWERS AND THUNDERSTORMS CHCS ARRIVING DURING THE DAY ON SUNDAY. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WITH RESPECT TO THUNDER WITH THE GFS MORE BULLISH OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PRECIPITATION EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE MODEL RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHOWER SLIGHT CHC/CHC WERE ADDED ATTM. TEMPERATURE-WISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH READINGS PRETTY CLOSE TO AVERAGE. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE COLD FRONT IS SLOWER IN ARRIVING. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 15Z-00Z...VFR WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... THURSDAY AND FRIDAY: VFR. GUSTY WNW WINDS 20-28 KTS DAYLIGHT HOURS DIMINISH AT NIGHT. CYCLONIC FLOW DOMINATES OUR WEATHER THROUGH FRIDAY WITH A SECONDARY WEAK COOL FRONTAL PASSAGE THURSDAY AFTERNOON OR EVENING. DIURNALLY HEAT DRIVEN CONSIDERABLE CLOUD COVER 3500 TO 5500 FT THURSDAY AND FRIDAY DAYLIGHT HOURS TENDS TO CLEAR AT NIGHT. MOST OF THE CLOUDINESS EASTERN PA AND NORTHERN TWO THIRDS OF NJ. SCT SHOWERS OR SPRINKLES POSSIBLE THURSDAY AFTERNOON POCONOS AND NORTHERN NJ WITH SHORT WAVE ROTATING SEWD THRU THE AREA AND A WEAK WIND SHIFT. SATURDAY...VFR LIGHT WIND AND HIGH PRESSURE OVERHEAD. SUNDAY...CONDITIONS MAY DEGRADE IN POTENTIAL LOW PRESSURE PASSAGE WITH MVFR CONDS IN SHOWERS. && .MARINE... TODAY...SCA THROUGH 00Z THU FOR NEARSHORE WATERS WITH GUSTS UP TO AROUND 25 KTS. SEAS 3 TO 5 FT ON THE OCEAN AND 2 TO 4 FEET IN THE BAY. TONIGHT...WINDS MAY CONTINUE OCCASIONALLY GUSTING 25 KTS VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD FROM THE COAST. THE EXCEPTION FOR TONIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY AND FRIDAY...NW WIND GUSTS 20-25 KNOTS. MIGHT BE A SECONDARY WEAK CFP LATE IN THE DAY THAT ENHANCES WIND TRANSFER INTO THU NIGHT. SATURDAY...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS. SUNDAY...DEGRADING CONDITIONS IN POTENTIAL SHOWERS AND LOW PRESSURE. && .FIRE WEATHER... FOLLOWING THE PASSAGE OF THE COLD FRONT THIS MORNING, MUCH DRIER AIR AND INCREASING WINDS WILL ARRIVE ACROSS THE AREA. THIS WILL ALLOW THE DEW POINTS TO TUMBLE AS WINDS INCREASE FROM THE WEST. MODEL FORECAST SOUNDINGS SUGGEST MIXING FROM 850 MB COULD DROP DEW POINTS INTO THE MID AND UPPER 40S THIS AFTERNOON. MODEL FORECAST SOUNDINGS ALSO SHOW THAT ABOUT 30 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE DEEPENING BOUNDARY LAYER THIS AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS OF 30 TO 35 MPH, MAINLY FROM LATE MORNING ON. GIVEN THE RATHER DRY CONDITIONS ACROSS THE REGION AND FORECAST WINDS AND RELATIVE HUMIDITY VALUES, THE START TIME FOR THE RED FLAG WARNING HAS BEEN MOVED UP TO NOON TODAY. WE ARE ANTICIPATING GUSTY WINDS ON THURSDAY, HOWEVER WITH COOLER TEMPERATURES THE RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER RELATED HEADLINES. A MENTION WILL BE INCLUDED ONLY IN THE FIRE WEATHER FORECAST FOR NOW. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ TODAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE THIS IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR PAZ060-061- 067>071. NJ...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NJZ009-010- 012>027. DE...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MDZ008-012- 015. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE/RPW NEAR TERM...DRAG/GORSE/RPW SHORT TERM...GORSE LONG TERM...GIGI/GORSE AVIATION...DRAG/KRUZDLO MARINE...DRAG/KRUZDLO FIRE WEATHER...HAYES/GORSE/RPW CLIMATE...637A 000 FXUS61 KAKQ 081452 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1052 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THROUGH THIS EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATCHING A DRY COLD FRONT MOVE INTO THE AREA THIS MORNING. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THE FRONT. STILL HAVE ISOLATED SHWRS POSSIBLE OVER NE NC THIS AFTERNOON. THE FRONT IS GENERATING QUITE A BIT OF CLOUD COVER...SO HAVE INCREASED CLOUDS FOR THE REMAINDER OF THE DAY TO PARTLY TO MOSTLY CLOUDY. THESE CLOUDS SHOULD INHIBIT TEMPS FORM REACHING THEIR FULLEST POTENTIAL THIS AFTERNOON. AS SUCH HAVE TRIMMED EXPECTED HIGH TEMPS BY A COUPLE OF DEGREES. PREVIOUS DISCUSSION BELOW... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... STILL GETTING 17-18 KT WAVES IN THE MIDDLE AND SRN BAY SO DECIDED TO EXTEND SCA UNTIL 2 PM. EXPECT WNDS TO DECREASE OVER THE WTRS THRU THE AFTERNOON AS LAND AREAS HEAT UP. ANOTHER SCA MIGHT HAVE TO BE RAISED LATER THIS EVENING OR TONIGHT AFTER FRONTAL BNDRY MOVES THRU THE WTRS. WNDS WILL THEN SHIFT TO NW-N OVERNIGHT INTO EARLY MORNING AND BRIEF SURGE BEHND TO FRONT MAY RAISE WNDS AND SEAS TO SCA FOR A SHORT PERIOD OF TIME. OTW HI PRES WILL GRADUALLY MOVE INTO THE REGION ON THU AND CONT DRY WX. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ631- 632. && $$ SYNOPSIS...BKH NEAR TERM...BKH/JDM SHORT TERM...BKH LONG TERM...LKB AVIATION...TMG MARINE...JEF 000 FXUS61 KPBZ 081431 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1031 AM EDT WED SEP 8 2010 .SYNOPSIS... COOL NORTHWEST WINDS WILL PREVAIL INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE THIS MORNING TO ADD PARTLY SUNNY TO AREAS NEAR PITTSBURGH AS STRATOCU ALREADY QUICKLY DEVELOPING AND ADVANCING SOUTHEAST. TEMPERATURES LOOK TO BE ON LINE AS WIND SHIFT WITH SECONDARY TROF AXIS AND COLD ADVECTION MOVES ACROSS OHIO THIS MORNING AND REMAINDER OF CWA THIS AFTERNOON. EXPECT SOME STRATUS TO HOLD ON INTO TONIGHT...BUT MOST DIMINISH WITH THE LOSS OF DIURNAL HEATING. WITH THE COOL NORTHWEST FLOW ACROSS THE LAKES ANTICIPATE SOME LAKE ENHANCED SHOWERS THIS AFTERNOON THROUGH TONIGHT NORTH. TEMPS NOT FAR FROM MODEL MOS. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... WITH SURFACE TROUGHING CONTINUING...ALONG WITH A RELATIVELY COOL NORTHWEST FLOW...STRATOCU DEVELOPMENT IS A GOOD BET THURSDAY...ESPECIALLY NORTH. IN ADDITION SPOTTY LAKE ENHANCED SHOWERS WILL BE POSSIBLE NORTHEAST THURSDAY. AS THE SURFACE RIDGE BUILDS INTO FRIDAY...CLOUD DEVELOPMENT WILL BE MINIMAL. TEMPS SHOULD RUN 5 TO 10 BELOW NORMAL DURING THIS PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... SKIES ARE CLEARING IN THE WAKE OF A COLD FRONT...WITH ALL AREAS HAVING FEW IF ANY CLOUDS THROUGH MID MORNING. NW FLOW WILL INCREASE BY THIS AFTN...ALLOWING FOR A STRATOCUMULUS DECK TO DEVELOP FROM PIT NORTHWARD. WILL USE LOW END VFR BROKEN CIGS WITH THIS DECK...WITH SCATTERED CLOUDS SOUTH OF A LBE/HLG LINE. AN ISOLATED SPRINKLE OR SHOWER IS ALSO POSSIBLE FOR FKL/DUJ THIS AFTN. WEST WINDS 4-8 KT THIS MORNING WILL INCREASE TO 12-18 KT THIS AFTN WITH GUSTS TO 25-30 KT POSSIBLE. CLOUDS WILL GRADUALLY ERODE TNGT AS HIGH PRESSURE BEGINS TO BUILD IN. VFR WILL PREVAIL FOR THURSDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KAKQ 081420 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1020 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THROUGH THIS EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATCHING A DRY COLD FRONT MOVE INTO THE AREA THIS MORNING. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THE FRONT. STILL HAVE ISOLATED SHWRS POSSIBLE OVER NE NC THIS AFTERNOON. THE FRONT IS GENERATING QUITE A BIT OF CLOUD COVER...SO HAVE INCREASED CLOUDS FOR THE REMAINDER OF THE DAY TO PARTLY TO MOSTLY CLOUDY. THESE CLOUDS SHOULD INHIBIT TEMPS FORM REACHING THEIR FULLEST POTENTIAL THIS AFTERNOON. AS SUCH HAVE TRIMMED EXPECTED HIGH TEMPS BY A COUPLE OF DEGREES. PREVIOUS DISCUSSION BELOW... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... SCA IN EFFECT FOR CHES BAY AND NRN TWO CSTL ZNS THRU 7 AM THIS MORNG DUE TO GUSTY SW WNDS IN ADVANCE OF COLD FRNT. FRNT THEN PUSHES ACRS THE AREA LATER THIS AFTN THRU THIS EVENG...WITH WNDS SHIFTING TO THE NW OR N OVRNGT INTO ERLY THU MORNG BEHIND THE BNDRY. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT...WITH NW OR N WNDS...WAVES AND SEAS REMAINING BELOW SCA CRITERIA. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...BKH NEAR TERM...BKH/JDM SHORT TERM...BKH LONG TERM...LKB AVIATION...TMG MARINE...TMG 000 FXUS61 KPHI 081223 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 823 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT IS CURRENTLY CROSSING OUR REGION AS LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND THROUGH TONIGHT. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA DURING THURSDAY AND FRIDAY. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE DURING SATURDAY, THEN A COLD FRONT WILL CROSS THE AREA SUNDAY. ANOTHER HIGH PRESSURE SYSTEM THEN BUILDS IN FOR MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A FEW LIGHT SHOWERS OR SPRINKLES CONTINUE ALONG THE COLD FRONT, WHICH WAS CROSSING THE DELAWARE RIVER FROM TRENTON TO WILMINGTON AT 8 AM. THE GRIDS HAVE BEEN UPDATED TO SHOW THIS. HAVE TAKEN OUT THE MENTION OF THUNDER, SINCE THE PORBABILITY OF THIS OCCURRING IS VERY LOW. THE FRONT, SHOWERS, AND CLOUDS WILL EXIT THE COAST BETWEEN 13 AND 15Z. SYNOPTICALLY, A STRONG UPPER-LEVEL TROUGH WILL BE MIGRATING FROM THE GREAT LAKES REGION TO THE NORTHEAST THROUGH TODAY. THE CYCLONIC FLOW BEHIND THE SURFACE COLD FRONT WILL ALLOW FOR INCREASING CAA WITH TIME. THE MAIN FOCUS TODAY IS THE PASSAGE OF A STRONG BUT MAINLY MOISTURE STARVED COLD FRONT. A DECENT AMOUNT OF CONVECTION FORMED AHEAD OF THE BOUNDARY EARLY LAST EVENING FROM THE EASTERN GREAT LAKES TO THE UPPER OHIO VALLEY, AS A RIBBON OF DEEPER MOISTURE COINCIDED WITH A RATHER IMPRESSIVE MIDLEVEL WIND MAX AND AN AXIS OF MLCAPE. THE BULK OF THIS IS LIFTING UP TO OUR NORTH, WEAKENING AND HEADED INTO NEW ENGLAND, HOWEVER SOME MODEST MIDLEVEL FLOW IS FORECAST TO CROSS OUR AREA. THIS IS THE DRIVING FORCE FOR THE SHOWERS THAT ARE CURRENTLY ACCOMPANYING THE FRONT. OTHERWISE, MAINLY MID TO HIGH LEVEL CLOUDS ALONG AND AHEAD OF THE COLD FRONT /PROBABLY BE ABLE TO ADVECT OR DEVELOP SOME CUMULUS AS WELL/, THEN FAIRLY QUICK CLEARING BEHIND THE COLD FRONT AS MUCH DRIER AIR ADVECTS IN ALONG WITH DEVELOPING CAA AND DOWNSLOPING FLOW. SOME GUSTINESS IN THE SOUTHERLY FLOW AHEAD OF THE COLD FRONT, THEN ADDITIONAL GUSTY WINDS BEHIND THE COLD FRONT AS THE LOW-LEVEL LAPSE RATES STEEPEN WITH THE DEVELOPING CAA ABOVE SURFACE HEATING. THE FORECAST SOUNDINGS INDICATE THAT THE WINDS INCREASE TO NEARLY 30 KNOTS AT THE TOP OF THE DEEPENING BOUNDARY LAYER. THIS WOULD TRANSLATE TO 30 TO 35 MPH WIND GUSTS BEHIND THE FRONT. THIS WILL PROBABLY BE DELAYED ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES AS THE FRONT ARRIVES HERE LATER. OVERALL, THE SITUATION LOOKS TO BE BELOW WIND ADVISORY CRITERIA. THE WINDS COMBINED WITH THE DRIER AIR SURGING IN BEHIND THE FRONT WILL LEAD TO FIRE WEATHER CONCERNS, THEREFORE SEE THE FIRE WEATHER SECTION BELOW FOR MORE DETAILS. AS FOR TEMPERATURES, GIVEN THE MILD START ACROSS THE BULK OF THE CWA UNDER WAA AHEAD OF THE COLD FRONT, LEANED TOWARD THE WARMER NAM MOS. THIS POINTS TOWARD WARMER TEMPERATURES ESPECIALLY ACROSS THE EASTERN AND SOUTHERN ZONES AS THE CAA WILL ARRIVE HERE IN EARNEST LATER IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN AREA OF LOW PRESSURE IS FORECAST TO BE NEAR NORTHERN NEW ENGLAND AS A CLOSED MIDLEVEL LOW SETS UP SHOP IN THAT VICINITY. THE ASSOCIATED LARGE TROUGH ENCOMPASSING THE NORTHEAST AND MID ATLANTIC STATES WILL RESULT IN A CYCLONIC FLOW BRINGING COOLER AIR TO THE REGION. THE NORTHWESTERLY FLOW OF THIS COOL AND DRY AIRMASS WILL ALLOW FOR LITTLE CLOUDS TO OCCUR TONIGHT. THE EXCEPTION SHOULD BE THE NORTHWESTERN ZONES WHERE THE CAA, COMBINED WITH THE FLOW OFF THE WARM EASTERN GREAT LAKES, CYCLONIC FLOW AND MOISTURE BECOMING TRAPPED UNDER AN INVERSION TO TOSS STRATOCUMULUS SOUTHEASTWARD. THEREFORE WE WILL CARRY MORE CLOUDS THERE THROUGH THE NIGHT AND ALSO DURING THURSDAY. THE WIND TONIGHT SHOULD DECOUPLE AT LEAST SOME, ALTHOUGH A COMPLETE DECOUPLING IS NOT ANTICIPATED GIVEN THE TIGHTENED PRESSURE GRADIENT AND CAA. THEREFORE, WE WILL GRADUALLY THROTTLE BACK ON THE WINDS. A FEW SHOWERS/SPRINKLES CANNOT BE RULED OUT MAINLY THURSDAY AFTERNOON THROUGH FRIDAY, THEREFORE SLIGHT CHC POPS WILL BE MAINTAINED AT TIMES FOR THE NORTHWESTERN ZONES. WE ARE SEEING A LITTLE INSTABILITY IN THE FORECAST SOUNDINGS THURSDAY AFTERNOON FARTHER SOUTH, THEREFORE CAA STRATOCUMULUS/CUMULUS WILL PROBABLY DEVELOP BUT POTENTIALLY FIGHT THE DOWNSLOPING FLOW /AS OF NOW WE ARE NOT ANTICIPATING ANY SPRINKLES OR BRIEF SHOWERS TO BE ABLE TO DEVELOP FROM THIS/. WE TRIED TO INDICATE THIS IN THE SKY COVER GRIDS FROM NORTHWEST TO SOUTHEAST. FOR FRIDAY, THE PRESSURE GRADIENT IS FORECAST TO GRADUALLY RELAX THEREFORE THE WINDS SHOULD NOT BE AS GUSTY COMPARED TO TODAY AND THURSDAY. AS FOR TEMPERATURES, WE GENERALLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE NAM/GFS MOS BUT MADE A FEW ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THIS TIME FRAME IS COMPRISED OF SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, LOW TEMPERATURES MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE HAVE SHOWERS AND THUNDERSTORMS CHCS ARRIVING DURING THE DAY ON SUNDAY. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WITH RESPECT TO THUNDER WITH THE GFS MORE BULLISH OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PRECIPITATION EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE MODEL RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHOWER SLIGHT CHC/CHC WERE ADDED ATTM. TEMPERATURE-WISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH READINGS PRETTY CLOSE TO AVERAGE. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE COLD FRONT IS SLOWER IN ARRIVING. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 11Z-14Z...VFR. A LINE OF SCT ELEVATED CONVECTION WILL PUSH EWD ACROSS THE FCST AREA. MOST OF IT SHOULD BE A 20 MINUTE SHOWER OR SPRINKLE HOWEVER...ISOLATED THUNDER IS EXPECTED. LINE "MAY" REIGNITE AS IT CROSSES THE COAST AROUND 1130Z-13Z? AFTER 14Z TODAY...VFR QUICKLY BECOMING SKC WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... THURSDAY AND FRIDAY: VFR. GUSTY WNW WINDS 20-28 KTS DAYLIGHT HOURS DIMINISH AT NIGHT. CYCLONIC FLOW DOMINATES OUR WEATHER THROUGH FRIDAY WITH A SECONDARY WEAK COOL FRONTAL PASSAGE THURSDAY AFTERNOON OR EVENING. DIURNALLY HEAT DRIVEN CONSIDERABLE CLOUD COVER 3500 TO 5500 FT THURSDAY AND FRIDAY DAYLIGHT HOURS TENDS TO CLEAR AT NIGHT. MOST OF THE CLOUDINESS EASTERN PA AND NORTHERN TWO THIRDS OF NJ. SCT SHOWERS OR SPRINKLES POSSIBLE THURSDAY AFTERNOON POCONOS AND NORTHERN NJ WITH SHORT WAVE ROTATING SEWD THRU THE AREA AND A WEAK WIND SHIFT. SATURDAY...VFR LIGHT WIND AND HIGH PRESSURE OVERHEAD. SUNDAY...CONDITIONS MAY DEGRADE IN POTENTIAL LOW PRESSURE PASSAGE WITH MVFR CONDS IN SHOWERS. && .MARINE... SCA THROUGH 00Z THU FOR NEAR SHORE /WITHIN 5 MI OF THE LAND/ GUSTS 25-30 KTS AFTER THE MORNING CFP. TONIGHT...WINDS MAY CONTINUE OCCASIONALLY GUSTING 25 KTS VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD FROM THE COAST. THE EXCEPTION FOR TONIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY AND FRIDAY...NW WIND GUSTS 20-25 KNOTS. MIGHT BE A SECONDARY WEAK CFP LATE IN THE DAY THAT ENHANCES WIND TRANSFER INTO THU NIGHT. SATURDAY...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS. SUNDAY...DEGRADING CONDITIONS IN POTENTIAL SHOWERS AND LOW PRESSURE. && .FIRE WEATHER... FOLLOWING THE PASSAGE OF THE COLD FRONT THIS MORNING, MUCH DRIER AIR AND INCREASING WINDS WILL ARRIVE ACROSS THE AREA. THIS WILL ALLOW THE DEW POINTS TO TUMBLE AS WINDS INCREASE FROM THE WEST. MODEL FORECAST SOUNDINGS SUGGEST MIXING FROM 850 MB COULD DROP DEW POINTS INTO THE MID AND UPPER 40S THIS AFTERNOON. MODEL FORECAST SOUNDINGS ALSO SHOW THAT ABOUT 30 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE DEEPENING BOUNDARY LAYER THIS AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS OF 30 TO 35 MPH, MAINLY FROM LATE MORNING ON. GIVEN THE RATHER DRY CONDITIONS ACROSS THE REGION AND FORECAST WINDS AND RELATIVE HUMIDITY VALUES, THE START TIME FOR THE RED FLAG WARNING HAS BEEN MOVED UP TO NOON TODAY. WE ARE ANTICIPATING GUSTY WINDS ON THURSDAY, HOWEVER WITH COOLER TEMPERATURES THE RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER RELATED HEADLINES. A MENTION WILL BE INCLUDED ONLY IN THE FIRE WEATHER FORECAST FOR NOW. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ TODAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE THIS IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR PAZ060-061-067>071. NJ...RED FLAG WARNING FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NJZ009-010-012>027. DE...RED FLAG WARNING FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR MDZ008-012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE/RPW NEAR TERM...DRAG/GORSE/RPW SHORT TERM...GORSE LONG TERM...GIGI/GORSE AVIATION...DRAG MARINE...DRAG FIRE WEATHER...HAYES/GORSE/RPW CLIMATE...637A 000 FXUS61 KPHI 081038 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 638 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT WILL SWEEP ACROSS THE REGION LATER THIS MORNING TO EARLY THIS AFTERNOON AS LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND THROUGH TONIGHT. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA DURING THURSDAY AND FRIDAY. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE DURING SATURDAY, THEN A COLD FRONT WILL CROSS THE AREA SUNDAY. ANOTHER HIGH PRESSURE SYSTEM THEN BUILDS IN FOR MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SCATTERED SHOWERS AND BAND OF CLOUDS IN N NJ AND SE PA AT 1030Z WILL EXIT THE COAST BETWEEN 13 AND 15Z. SYNOPTICALLY, A STRONG UPPER-LEVEL TROUGH WILL BE MIGRATING FROM THE GREAT LAKES REGION TO THE NORTHEAST THROUGH TODAY. THE CYCLONIC FLOW BEHIND THE SURFACE COLD FRONT WILL ALLOW FOR INCREASING CAA WITH TIME. THE MAIN FOCUS TODAY IS THE PASSAGE OF A STRONG BUT MAINLY MOISTURE STARVED COLD FRONT. THIS BOUNDARY IS FORECAST TO CROSS THE CWA FROM LATER THIS MORNING TO ABOUT THE EARLY AFTERNOON HOURS FROM WEST TO EAST. A DECENT AMOUNT OF CONVECTION FORMED AHEAD OF THE BOUNDARY EARLY LAST EVENING FROM THE EASTERN GREAT LAKES TO THE UPPER OHIO VALLEY, AS A RIBBON OF DEEPER MOISTURE COINCIDED WITH A RATHER IMPRESSIVE MIDLEVEL WIND MAX AND AN AXIS OF MLCAPE. THE BULK OF THIS IS LIFTING UP TO OUR NORTH, WEAKENING AND HEADED INTO NEW ENGLAND, HOWEVER SOME MODEST MIDLEVEL FLOW IS FORECAST TO CROSS OUR AREA. THIS MAY TEND TO KEEP AT LEAST SOME ELEVATED INSTABILITY ACROSS THE CWA ESPECIALLY NORTHEASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY. THE QUESTION IS WHETHER THE CONVECTION CAN MAKE IT INTO OUR AREA THIS MORNING OR REDEVELOP. THE GFS APPEARS TO BE A BIT SLOW WITH THE BACK EDGE OF THE CONVECTION. THE 12Z/07 SPC 4KM WRF HAD A GOOD HANDLE ON THE TIMING AND AREAL EVOLUTION OF THIS CONVECTION LAST EVENING AND TRENDS SO FAR EARLY THIS MORNING, THEREFORE AM INCLINED TO FOLLOW THIS A BIT CLOSER. THEREFORE, WE WILL JUST STICK WITH MAINLY SOME SLIGHT CHC TO LOW END CHC POPS ACROSS THE NORTHERN AREAS THIS MORNING TO EARLY AFTERNOON. SOME ACTIVITY HAS BEEN REDEVELOPING ACROSS SOUTH-CENTRAL PENNSYLVANIA SO THIS WILL BE MONITORED AND SOME POP ADJUSTMENTS MAY BE NEEDED WITH THE 09Z UPDATE. OTHERWISE, MAINLY MID TO HIGH LEVEL CLOUDS ALONG AND AHEAD OF THE COLD FRONT /PROBABLY BE ABLE TO ADVECT OR DEVELOP SOME CUMULUS AS WELL/, THEN FAIRLY QUICK CLEARING BEHIND THE COLD FRONT AS MUCH DRIER AIR ADVECTS IN ALONG WITH DEVELOPING CAA AND DOWNSLOPING FLOW. SOME GUSTINESS IN THE SOUTHERLY FLOW AHEAD OF THE COLD FRONT, THEN ADDITIONAL GUSTY WINDS BEHIND THE COLD FRONT AS THE LOW-LEVEL LAPSE RATES STEEPEN WITH THE DEVELOPING CAA ABOVE SURFACE HEATING. THE FORECAST SOUNDINGS INDICATE THAT THE WINDS INCREASE TO NEARLY 30 KNOTS AT THE TOP OF THE DEEPENING BOUNDARY LAYER. THIS WOULD TRANSLATE TO 30 TO 35 MPH WIND GUSTS BEHIND THE FRONT. THIS WILL PROBABLY BE DELAYED ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES AS THE FRONT ARRIVES HERE LATER. OVERALL, THE SITUATION LOOKS TO BE BELOW WIND ADVISORY CRITERIA. THE WINDS COMBINED WITH THE DRIER AIR SURGING IN BEHIND THE FRONT WILL LEAD TO FIRE WEATHER CONCERNS, THEREFORE SEE THE FIRE WEATHER SECTION BELOW FOR MORE DETAILS. AS FOR TEMPERATURES, GIVEN THE MILD START ACROSS THE BULK OF THE CWA UNDER WAA AHEAD OF THE COLD FRONT, LEANED TOWARD THE WARMER NAM MOS. THIS POINTS TOWARD WARMER TEMPERATURES ESPECIALLY ACROSS THE EASTERN AND SOUTHERN ZONES AS THE CAA WILL ARRIVE HERE IN EARNEST LATER IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN AREA OF LOW PRESSURE IS FORECAST TO BE NEAR NORTHERN NEW ENGLAND AS A CLOSED MIDLEVEL LOW SETS UP SHOP IN THAT VICINITY. THE ASSOCIATED LARGE TROUGH ENCOMPASSING THE NORTHEAST AND MID ATLANTIC STATES WILL RESULT IN A CYCLONIC FLOW BRINGING COOLER AIR TO THE REGION. THE NORTHWESTERLY FLOW OF THIS COOL AND DRY AIRMASS WILL ALLOW FOR LITTLE CLOUDS TO OCCUR TONIGHT. THE EXCEPTION SHOULD BE THE NORTHWESTERN ZONES WHERE THE CAA, COMBINED WITH THE FLOW OFF THE WARM EASTERN GREAT LAKES, CYCLONIC FLOW AND MOISTURE BECOMING TRAPPED UNDER AN INVERSION TO TOSS STRATOCUMULUS SOUTHEASTWARD. THEREFORE WE WILL CARRY MORE CLOUDS THERE THROUGH THE NIGHT AND ALSO DURING THURSDAY. THE WIND TONIGHT SHOULD DECOUPLE AT LEAST SOME, ALTHOUGH A COMPLETE DECOUPLING IS NOT ANTICIPATED GIVEN THE TIGHTENED PRESSURE GRADIENT AND CAA. THEREFORE, WE WILL GRADUALLY THROTTLE BACK ON THE WINDS. A FEW SHOWERS/SPRINKLES CANNOT BE RULED OUT MAINLY THURSDAY AFTERNOON THROUGH FRIDAY, THEREFORE SLIGHT CHC POPS WILL BE MAINTAINED AT TIMES FOR THE NORTHWESTERN ZONES. WE ARE SEEING A LITTLE INSTABILITY IN THE FORECAST SOUNDINGS THURSDAY AFTERNOON FARTHER SOUTH, THEREFORE CAA STRATOCUMULUS/CUMULUS WILL PROBABLY DEVELOP BUT POTENTIALLY FIGHT THE DOWNSLOPING FLOW /AS OF NOW WE ARE NOT ANTICIPATING ANY SPRINKLES OR BRIEF SHOWERS TO BE ABLE TO DEVELOP FROM THIS/. WE TRIED TO INDICATE THIS IN THE SKY COVER GRIDS FROM NORTHWEST TO SOUTHEAST. FOR FRIDAY, THE PRESSURE GRADIENT IS FORECAST TO GRADUALLY RELAX THEREFORE THE WINDS SHOULD NOT BE AS GUSTY COMPARED TO TODAY AND THURSDAY. AS FOR TEMPERATURES, WE GENERALLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE NAM/GFS MOS BUT MADE A FEW ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THIS TIME FRAME IS COMPRISED OF SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, LOW TEMPERATURES MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE HAVE SHOWERS AND THUNDERSTORMS CHCS ARRIVING DURING THE DAY ON SUNDAY. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WITH RESPECT TO THUNDER WITH THE GFS MORE BULLISH OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PRECIPITATION EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE MODEL RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHOWER SLIGHT CHC/CHC WERE ADDED ATTM. TEMPERATURE-WISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH READINGS PRETTY CLOSE TO AVERAGE. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE COLD FRONT IS SLOWER IN ARRIVING. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 11Z-14Z...VFR. A LINE OF SCT ELEVATED CONVECTION WILL PUSH EWD ACROSS THE FCST AREA. MOST OF IT SHOULD BE A 20 MINUTE SHOWER OR SPRINKLE HOWEVER...ISOLATED THUNDER IS EXPECTED. LINE "MAY" REIGNITE AS IT CROSSES THE COAST AROUND 1130Z-13Z? AFTER 14Z TODAY...VFR QUICKLY BECOMING SKC WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... THURSDAY AND FRIDAY: VFR. GUSTY WNW WINDS 20-28 KTS DAYLIGHT HOURS DIMINISH AT NIGHT. CYCLONIC FLOW DOMINATES OUR WEATHER THROUGH FRIDAY WITH A SECONDARY WEAK COOL FRONTAL PASSAGE THURSDAY AFTERNOON OR EVENING. DIURNALLY HEAT DRIVEN CONSIDERABLE CLOUD COVER 3500 TO 5500 FT THURSDAY AND FRIDAY DAYLIGHT HOURS TENDS TO CLEAR AT NIGHT. MOST OF THE CLOUDINESS EASTERN PA AND NORTHERN TWO THIRDS OF NJ. SCT SHOWERS OR SPRINKLES POSSIBLE THURSDAY AFTERNOON POCONOS AND NORTHERN NJ WITH SHORT WAVE ROTATING SEWD THRU THE AREA AND A WEAK WIND SHIFT. SATURDAY...VFR LIGHT WIND AND HIGH PRESSURE OVERHEAD. SUNDAY...CONDITIONS MAY DEGRADE IN POTENTIAL LOW PRESSURE PASSAGE WITH MVFR CONDS IN SHOWERS. && .MARINE... SCA THROUGH 00Z THU FOR NEAR SHORE /WITHIN 5 MI OF THE LAND/ GUSTS 25-30 KTS AFTER THE MORNING CFP. TONIGHT...WINDS MAY CONTINUE OCCASIONALLY GUSTING 25 KTS VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD FROM THE COAST. THE EXCEPTION FOR TONIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY AND FRIDAY...NW WIND GUSTS 20-25 KNOTS. MIGHT BE A SECONDARY WEAK CFP LATE IN THE DAY THAT ENHANCES WIND TRANSFER INTO THU NIGHT. SATURDAY...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS. SUNDAY...DEGRADING CONDITIONS IN POTENTIAL SHOWERS AND LOW PRESSURE. && .FIRE WEATHER... FOLLOWING THE PASSAGE OF A COLD FRONT LATER THIS MORNING AND EARLY THIS AFTERNOON, MUCH DRIER AIR AND INCREASING WINDS WILL ARRIVE ACROSS THE AREA. THIS WILL ALLOW THE DEW POINTS TO TUMBLE AS WINDS INCREASE FROM THE WEST. MODEL FORECAST SOUNDINGS SUGGEST MIXING FROM 850 MB COULD DROP DEW POINTS INTO THE MID AND UPPER 40S THIS AFTERNOON. MODEL FORECAST SOUNDINGS ALSO SHOW THAT ABOUT 30 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE DEEPENING BOUNDARY LAYER THIS AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS OF 30 TO 35 MPH, MAINLY FROM LATE MORNING ON. A POSSIBLE FLY IN THE OINTMENT IS THAT IF THE COLD FRONT IS SLOWER IN CLEARING THE AREA, THEN THE TIGHTENING PRESSURE GRADIENT AND CAA WOULD BE DELAYED RESULTING IN A DELAY OF THE GUSTY WINDS AND DRIER AIR. GIVEN THE RATHER DRY CONDITIONS ACROSS THE REGION AND FORECAST WINDS AND RELATIVE HUMIDITY VALUES, THE RED FLAG WARNING WILL BE MAINTAINED AS IS FOR NOW. DEPENDING THOUGH ON RELATIVE HUMIDITY AND WIND TRENDS, SOME EXPANSION OF THE WARNING MAY BE NEEDED LATER ESPECIALLY FOR THE FAR SOUTHERN AREAS. WE ARE ANTICIPATING GUSTY WINDS ON THURSDAY, HOWEVER WITH COOLER TEMPERATURES THE RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER RELATED HEADLINES. A MENTION WILL BE INCLUDED ONLY IN THE FIRE WEATHER FORECAST FOR NOW. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ TODAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE THIS IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR PAZ060-061-067>071. NJ...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR NJZ009-010-012>027. DE...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR MDZ008-012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE NEAR TERM...DRAG/GORSE 637A SHORT TERM...GORSE LONG TERM...GIGI/GORSE AVIATION...DRAG 637A MARINE...DRAG 637A FIRE WEATHER... CLIMATE...637A 000 FXUS61 KPBZ 080917 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 518 AM EDT WED SEP 8 2010 .SYNOPSIS... WEAK SURFACE TROUGHING WILL LINGER THROUGH THURSDAY. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AFTER A PERIOD OF MAINLY SUNNY SKIES THIS MORNING...STRATOCU SHOULD DEVELOP IN A MOIST LAYER AROUND 850MB. TEMPS WILL BE ABOUT 15 TO 20 DEGREES COOLER TODAY THAN ON TUESDAY...WITH WINDS STILL A LITTLE GUSTY. BASED ON FORECAST RH AND WINDS...SOUTHEAST MOUNTAINS WILL HAVE THE BEST FIRE WEATHER POTENTIAL TODAY. BUT AGAIN THIS AREA DOES NOT MEET CRITERIA FOR A RED FLAG...BASED ON CURRENT FORECAST. DEWPOINT AND TEMPERATURE TRENDS WILL NEED TO BE MONITORED LATER THIS MORNING INTO EARLY AFTERNOON...TO ASSESS FIRE WEATHER POTENTIAL. EXPECT SOME STRATUS TO HOLD ON INTO TONIGHT...BUT MOST DIMINISH WITH THE LOSS OF DIURNAL HEATING. WITH THE COOL NORTHWEST FLOW ACROSS THE LAKES ANTICIPATE SOME LAKE ENHANCED SHOWERS THIS AFTERNOON THROUGH TONIGHT NORTH. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... WITH SURFACE TROUGHING CONTINUING...ALONG WITH A RELATIVELY COOL NORTHWEST FLOW...STRATOCU DEVELOPMENT IS A GOOD BET THURSDAY...ESPECIALLY NORTH. IN ADDITION SPOTTY LAKE ENHANCED SHOWERS WILL BE POSSIBLE NORTHEAST THURSDAY. AS THE SURFACE RIDGE BUILDS INTO FRIDAY...CLOUD DEVELOPMENT WILL BE MINIMAL. TEMPS SHOULD RUN 5 TO 10 BELOW NORMAL DURING THIS PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... SKIES ARE CLEARING IN THE WAKE OF A COLD FRONT...WITH ALL AREAS HAVING FEW IF ANY CLOUDS THROUGH MID MORNING. NW FLOW WILL INCREASE BY THIS AFTN...ALLOWING FOR A STRATOCUMULUS DECK TO DEVELOP FROM PIT NORTHWARD. WILL USE LOW END VFR BROKEN CIGS WITH THIS DECK...WITH SCATTERED CLOUDS SOUTH OF A LBE/HLG LINE. AN ISOLATED SPRINKLE OR SHOWER IS ALSO POSSIBLE FOR FKL/DUJ THIS AFTN. WEST WINDS 4-8 KT THIS MORNING WILL INCREASE TO 12-18 KT THIS AFTN WITH GUSTS TO 25-30 KT POSSIBLE. CLOUDS WILL GRADUALLY ERODE TNGT AS HIGH PRESSURE BEGINS TO BUILD IN. VFR WILL PREVAIL FOR THURSDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPBZ 080853 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 453 AM EDT WED SEP 8 2010 .SYNOPSIS... WEAK SURFACE TROUGHING WILL LINGER THROUGH THURSDAY. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AFTER A PERIOD OF MAINLY SUNNY SKIES THIS MORNING...STRATOCU SHOULD DEVELOP IN A MOIST LAYER AROUND 850MB. TEMPS WILL BE ABOUT 15 TO 20 DEGREES COOLER TODAY THAN ON TUESDAY...WITH WINDS STILL A LITTLE GUSTY. BASED ON FORECAST RH AND WINDS...SOUTHEAST MOUNTAINS WILL HAVE THE BEST FIRE WEATHER POTENTIAL TODAY. BUT AGAIN THIS AREA DOES NOT MEET CRITERIA FOR A RED FLAG...BASED ON CURRENT FORECAST. DEWPOINT AND TEMPERATURE TRENDS WILL NEED TO BE MONITORED LATER THIS MORNING INTO EARLY AFTERNOON...TO ASSESS FIRE WEATHER POTENTIAL. EXPECT SOME STRATUS TO HOLD ON INTO TONIGHT...BUT MOST DIMINISH WITH THE LOSS OF DIURNAL HEATING. WITH THE COOL NORTHWEST FLOW ACROSS THE LAKES ANTICIPATE SOME LAKE ENHANCED SHOWERS THIS AFTERNOON THROUGH TONIGHT NORTH. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... WITH SURFACE TROUGHING CONTINUING...ALONG WITH A RELATIVELY COOL NORTHWEST FLOW...STRATOCU DEVELOPMENT IS A GOOD BET THURSDAY...ESPECIALLY NORTH. IN ADDITION SPOTTY LAKE ENHANCED SHOWERS WILL BE POSSIBLE NORTHEAST THURSDAY. AS THE SURFACE RIDGE BUILDS INTO FRIDAY...CLOUD DEVELOPMENT WILL BE MINIMAL. TEMPS SHOULD RUN 5 TO 10 BELOW NORMAL DURING THIS PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... SKIES ARE CLEARING IN THE WAKE OF A COLD FRONT...WITH ALL AREAS HAVING FEW IF ANY CLOUDS THROUGH MID MORNING. NW FLOW WILL INCREASE BY THIS AFTN...ALLOWING FOR A STRATOCUMULUS DECK TO DEVELOP FROM PIT NORTHWARD. WILL USE LOW END VFR BROKEN CIGS WITH THIS DECK...WITH SCATTERED CLOUDS SOUTH OF A LBE/HLG LINE. AN ISOLATED SPRINKLE OR SHOWER IS ALSO POSSIBLE FOR FKL/DUJ THIS AFTN. CLOUDS WILL GRADUALLY ERODE TNGT AS HIGH PRESSURE BEGINS TO BUILD IN. VFR WILL PREVAIL FOR THURSDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KAKQ 080840 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 440 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THIS AFTERNOON AND EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... EXPECTING VFR CONDITIONS TDY INTO THU MORNG...AS A DRY COLD FRNT SWINGS ACRS THE AREA. JUST CI AND HIGH AC IN ADVANCE OF AND WITH THE FRNT...AND POSSIBLY SOME LGT FOG BEHIND IT. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT WITH VFR CONDITIONS CONTINUING. LWR CIGS/VSBYS POSSIBLE SAT NGT AND SUN...AS ANOTHER COLD FRNT APPROACHES AND MOVES THRU. && .MARINE... SCA IN EFFECT FOR CHES BAY AND NRN TWO CSTL ZNS THRU 7 AM THIS MORNG DUE TO GUSTY SW WNDS IN ADVANCE OF COLD FRNT. FRNT THEN PUSHES ACRS THE AREA LATER THIS AFTN THRU THIS EVENG...WITH WNDS SHIFTING TO THE NW OR N OVRNGT INTO ERLY THU MORNG BEHIND THE BNDRY. HI PRES BLDS INTO AND OVR THE REGION FOR THU INTO SAT...WITH NW OR N WNDS...WAVES AND SEAS REMAINING BELOW SCA CRITERIA. ANOTHER COLD FRNT MOVES THRU THE AREA SUN. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ630>632-650-652. && $$ SYNOPSIS...BKH NEAR TERM...BKH SHORT TERM...BKH LONG TERM...LKB AVIATION...TMG MARINE...TMG 000 FXUS61 KAKQ 080806 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 406 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION THIS AFTERNOON AND EVENING...THEN DROP SOUTH OF THE NORTH CAROLINA OUTER BANKS THURSDAY MORNING. HIGH PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND... WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST SFC ANALYSIS SHOWS COLD FRONT ACROSS THE OH VLY. STLT WV/IR LOOPS SHOW A RATHER DISJOINTED WARM CONVEYOR BELT (WCB) PROFILE...LARGELY DUE TO THE ANTICYCLONIC EFFECTS BTWN THE DEEP LOW N OF THE ERN GREAT LAKES AND THE REMNANTS OF HERMINE OVER TX. ZONAL FLOW BTWN THESE 2 SYSTEMS HAS EXTENDED THE OUTER CI/CS SHIELD OF HERMINE WELL E...NOW INTO THE MID ATLC REGION...WHILE MID LVL DEFORMATION IS FAIRLY NOTICEABLE WITH THE SHARP NRN EDGE TO THE HIGHER CLOUD TOPS. GIVEN THE ABSENCE OF FVRBL QG FORCING/DEEP MSTR BTWN THE MAIN CIRCULATION CENTERS...COMPOSITE RADARS SHOW NOT MUCH MORE THAN SCT SHOWERS OVER THE MNTS ASSCD WITH THE COLD FRONT. THE CONCERN FOR OUR REGION IN TERMS OF RAIN CHANCES IS WHAT THE DOWNSLOPING W/WSW PRE FRONTAL LLVL FLOW WILL DO TO THESE POCKETS OF SHOWERS ONCE THEY PUSH E OF THE MNTNS. GIVEN THE DEPTH OF THE WRLY FLOW... BOTH THE GFS/NAM MODEL SOUNDINGS SHOW CONSIDERABLE DRYING IN THE LOWER LAYERS TODAY PER THE DOWNSLOPE EFFECTS...AND GIVEN THE NEGLIGIBLE UPPER LVL DYNAMICS (MORE RRQ OR RIGHT EXIT REGION UPR FORCING THAN OTHERWISE)...HAVE KEPT POPS OUT OF THE FCST TODAY OVER THE BULK OF THE FCST AREA. AT THIS POINT IS CONTINUES TO APPEAR THE AREA WITH THE BEST CHANCE FOR ANY ORGANIZED HIGH-BASED CU FIELD AND ISOLD CONVECTION AHEAD OF THE FRONT WILL BE ACROSS THE NERN NC ZONES...IN AN AREA WHERE LLVL MOISTURE PROFILES (MSTR FLUX CONVERGENCE AHEAD OF THE FRONT) WILL BE SLIGHTLY MORE FVRBL...WHILE DOWNSLOPING DRYING EFFECTS ARE NOT AS PRONOUNCED. AT MOST...LOOKING AT 15-20% PROBABILITY/COVERAGE. 1000-850 MB THICKNESSES PEAKING AT 1420-1425M THIS AFTN...COUPLED WITH THE DOWNSLOPE FLOW...SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S...WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION...IT WILL BE A BIT BREEZY THIS AFTN...AS SOUNDINGS CONTINUE TO SUGGEST A FAIRLY SIGNIFICANT DIURNAL GUST FACTOR OVER LAND...WITH AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR TONIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD...WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS...WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... SURFACE OBS SHOWING CLEAR SKIES AND LIGHT S WINDS. WINDS WILL REMAIN A BIT HIGHER TONIGHT AND WILL PREVENT ANY FOG FORMATION AT THE TAF SITES. HIGH CLOUDS WILL BEGIN TO COME IN WED MORNING AHEAD OF THE COLD FRONT AND WILL THICKEN AND LOWER THROUGHOUT THE DAY. VFR CONDITIONS ARE STILL EXPECTED ALL DAY WED. EXPECT WINDS TO PICK UP AND SHIFT TO THE W DURING THE DAY. VFR CONDITIONS WILL PREVAIL AS HIGH PRESSURE BUILDS BACK INTO THE AREA THROUGH SAT. && .MARINE... CURRENT OBSERVATIONS INDICATE THE WIND IS INCREASING OVER THE LOWER BAY AND NEARING SMALL CRAFT CRITERIA. ADDITIONALLY...THE LATEST HIGH RESOLUTION MODEL GUIDANCE SUGGESTS A PERIOD OF MARGINAL SMALL CRAFT CONDITIONS THROUGH THE EVENING AND OVERNIGHT HOURS. HENCE A SMALL CRAFT FLAG WAS RAISED FOR THE LOWER BAY COINCIDENT WITH THE INHERITED FLAG TO THE NORTH. OTHERWISE...THERE WERE NO CHANGES TO THE LATEST MARINE FORECAST. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA INTO A DEVELOPING LEE TROUGH...EXPECT A WIND SHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY DELTA TEMPS AROUND 12C WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. EXPECT JUST A BRIEF PERIOD OF THESE CONDITIONS OVERNIGHT. -BLAES && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ630>632-650-652. && $$ SYNOPSIS...BKH NEAR TERM...BKH SHORT TERM...BKH LONG TERM...LKB AVIATION...TMG MARINE...TMG 000 FXUS61 KLWX 080743 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 343 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION THIS MORNING...BRINGING BREEZY CONDITIONS. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND PERSIST INTO THE WEEKEND. ANOTHER COLD FRONT WILL IMPACT THE REGION SUNDAY...WHICH WILL BE FOLLOWED BY MORE HIGH PRESSURE. && .NEAR TERM /TODAY/... ANOTHER DAY OF RECORD BRKG HEAT YDA...W/ BWI HITTING ITS 55TH DAY OF 90 DEG OR BETTER TEMPS. ATMOSPHERE IS CERTAINLY BACK IN MOTION THO...W/ CD FNT PRSNTLY ENTERING WRN W.V. IS XPCTD TO MOVE OUT OF THE APLCHNS ARND 15Z. ANY RW ASSO W/ THIS FNT WL BE ISOLD AT BEST IN THE HIGHLANDS AND ENDING BY MID MRNG. UNFORTUNATELY WE NEED THE RAIN AND THERE IS NONE ON THE HORIZON - SEE FIRE WX SXN BLO. WINDS WL TURN TO THE W BEHIND THE FNT AND INCRS THIS AFTN PRODUCING GUSTY 25 KT GUSTS. A DAY TO FLY A KITE? AFTR SCT-BKN MRNG CLDS SKIES SHOULD CLR PRETTY QUICKLY THIS AFTN. W/ XCPTN OF ONE DAY IN MY STRING OF SIX MIDS MDLS HV UNDERDONE HIGH TEMPS EVERY DAY. GIVEN THE HIGH STARTING PT (IT`S 81 AT DMH AT 2 AM...M70S OVR MUCH OF THE RMNDR OF THE AREA)...WARMTH THE GRND AND CHES BAY CURRENTLY POSSESS...AND AFTN SUN I`LL CONT THE TREND OF KEEPING IT VERY WARM...ANOTHER PSBLTY OF HITTING 90 IN BALT CITY/DC/ALONG THE BAY. MUCH OF E OF THE MTNS WL TOP OUT IN THE U80S...HIGHLANDS WL BE COOLEST IN THE MU70S. && .SHORT TERM /TONIGHT/... TNGT THINGS WL SETTLE DOWN AS HIGH PRES BLDS INTO THE RGN. CLR SKIES. WINDS SHOULD DECOUPLE AFTR MDNGT AS LO LVL INVRSN FORMS. IN SPITE OF THE POST FRONTAL CAA ENVIRONMENT I HV LOW TEMPS FAIRLY CLOSE TO CLIMO NORMS FOR THE 2ND WK OF SEP...RANGING FM MU40S IN THE HIGHLANDS...50S MUCH OF THE AREA...LM60S IN CITIES/ALONG THE BAY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... TROF-RIDGE-TROF FOR THE CONUS FOR THE SECOND-HALF OF THE WEEK. THE FIRST TROF WILL BE SLOWLY DRIFTING OVER THE ST LAWRENCE CHANNEL THU/FRI. THE FURTHER EAST THIS FEATURE MOVES...THE WARMER AND LESS WINDY THE MID ATLC WILL BE. CONSEQUENTLY...THE BREEZY CONDITIONS THAT WE/LL SEE TODAY POST-FRONTAL WILL BE SUBSIDING A BIT EACH AFTN...THOUGH THE END OF THE WEEK. NEXT...THE REMNANTS OF HERMINE WILL DRIFT INTO THE MID MS VLY ON FRI...EMBEDDED IN THE WEAK UPPER RIDGE OVER THE CNTRL PLAINS. THE REMNANT LOW WILL BE ABSORBED INTO ANOTHER APPROACHING UPPER TROF /THE SECOND TROF FEATURE/ THAT WILL BE STRENGTHENING OVER THE NRN ROCKIES/PLAINS - MUCH LIKE THE FIRST LOW PRESSURE SYSTEM HAS DONE OVER THE PAST COUPLE OF DAYS. A STRONG ZONAL PATTERN OVER MUCH OF THE COUNTRY /OR A WEAK BUT LARGE AND ELONGATED RIDGE OVER THE SRN HALF OF THE CONUS/ WILL SETTLE IN BY SUNDAY. THIS SCENARIO LOOKS LIKE IT WILL BE THE STORY FOR MUCH OF NEXT WEEK. THE ONLY FEATURES AFFECTING THE REGION DURING THIS PERIOD WOULD BE ON SUNDAY...AS THE SECOND TROF SLIDES ACROSS THE ERN SEABOARD AND PUSHES A WEAK COLD FRONT ACROSS THE MID ATLC. THE OTHER FEATURE WOULD BE ANOTHER WEAK UPPER SHORT WAVE SWINGING DOWN FROM THE GREAT LAKES REGION TUE INTO WED OF NEXT WEEK. TEMPS/DEWPOINTS WILL BECOME MORE STEADILY SEASONABLE DURING THIS LONG RANGE PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS TDA/TNGT. XPCT WINDS TO SHIFT TO THE W ARND NOON AND BECOME GUSTY THIS AFTN. CLR SKIES AND LGT WINDS AFTR 00Z. VFR CONDITIONS FOR THE LONG RANGE. A COLD FRONT WILL MOVE THROUGH ON SUNDAY...BRINGING THE BEST CHANCE FOR SCATTERED SHOWERS /AND A LOW CHANCE AT THAT/. WINDS WOULD BE THE MAIN CONCERN W/ 15-20KT GUSTS POSSIBLE THU AND FRI AFTN. && .MARINE... SCA CURRENTLY IN EFFECT AND WL RMN SO THRU THE DAY AND EVE HRS ACROSS ALL THE WATERS. GIVEN CAA OVR XTRMLY WARM WATERS WINDS WL CONTINUE TO BE GUSTY OVR THE BAY AND LOWER PTMC OVRNGT. INCREASING WINDS DURING EACH AFTN FOR THE NEXT FEW DAYS...MAINLY THU AND FRI FOR THE LONG RANGE FORECAST. NWLY FLOW WILL INCREASE DURING THE MID MORNING HRS EACH DAY AND PEAK LATE AFTN/EVE...FOR MORE LIKELY CONTINUED SCA CONDITIONS THROUGH THE END OF THE WORK WEEK. WINDS SHOULD DECREASE FOR WEEKEND AS HIGH PRESSURE BRIEFLY MOVES LATE FRI/SAT...BUT THEN ANOTHER COLD FRONT MOVES THROUGH ON SUNDAY. && .FIRE WEATHER... ***GOV OF W.V. HAS ISSUED A BURNING BAN FOR ERN WV PANHANDLE WHICH WILL CONTINUE UNTIL FURTHER NOTICE.*** EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE... GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. A COLD FRONT WILL MOVE THRU THE REGION THIS MRNG. BREEZY CONDITIONS WILL OCCUR THIS AFTN BEHIND THE FRONT. RED FLAG CONDITIONS ARE POSSIBLE WITH SUSTAINED WINDS APPROACHING 20 MPH AND MIN AFTN RH VALUES BETWEEN 25-30 PERCENT COMBINED WITH THE ALREADY LOW FUEL MOISTURE. A FIRE WEATHER WATCH IS IN EFFECT FOR MOST OF THE CWFA...WITH THE EXCLUSION OF THE NRN PIEDMONT AND CENTRAL FOOTHILLS IN VA. DAYSHIFT WILL COORDINATE WITH STATE FIRE OFFICIALS THIS MRNG WHEN WRNG HEADLINE DECISIONS ARE MADE. NWLY FLOW WILL CONTINUE FOR THURSDAY AND FRIDAY...MAINTAINING AN ENHANCED FIRE WX THREAT. && .TIDES/COASTAL FLOODING... MRGNL COASTAL FLOOD ADVISORY REMAINS IN EFFECT FOR MINOR TIDAL FLOODING ALONG OUR TIDAL SHORELINE THRU THE MRNG TIDAL CYCLE. S WINDS HV BEEN PUSHING WATER UP THE BAY. WED MORNINGS HIGH TIDE IS THE HIGHER OF THE TWO DAILY ASTRONOMICAL TIDES..HENCE THE TIDES THIS MORN SHOULD BE SLIGHTLY ABOVE WHAT THEY WERE IN THE EVENING...ALTHO ATTM DC TIDE LVL IS NEARLY AT NRML...AND CALLED THE ALEXANDRIA EM OFFICE WHICH REPORTED NO PROBS W/ THE PRVS CYCLE. WINDS WL TURN TO THE W/NW THIS AFTN...ENDING THIS CSTL FLD THREAT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FIRE WEATHER WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS AFTERNOON FOR DCZ001. COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR DCZ001. MD...FIRE WEATHER WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS AFTERNOON FOR MDZ003>007-009>011-013-014-016>018-501-502. COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MDZ007- 011-013-014-016>018. VA...FIRE WEATHER WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS AFTERNOON FOR VAZ021-025>031-038>040-042-051>054-501-502. COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR VAZ052>055-057. WV...FIRE WEATHER WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS AFTERNOON FOR WVZ050>055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ531>534- 537-539>541-543. SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR ANZ535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 AM EDT THURSDAY FOR ANZ530. && $$ PRODUCTS...WOODY!/GMS 000 FXUS61 KPHI 080732 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 332 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT WILL SWEEP ACROSS THE REGION LATER THIS MORNING TO EARLY THIS AFTERNOON AS LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND THROUGH TONIGHT. AN AREA OF HIGH PRESSURE THEN GRADUALLY BUILDS INTO OUR AREA DURING THURSDAY AND FRIDAY. THIS HIGH PRESSURE SYSTEM WILL MOVE OFFSHORE DURING SATURDAY, THEN A COLD FRONT WILL CROSS THE AREA SUNDAY. ANOTHER HIGH PRESSURE SYSTEM THEN BUILDS IN FOR MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A 06Z SURFACE ANALYSIS PLACED LOW PRESSURE NEAR HUDSON BAY AND A TRAILING COLD FRONT WAS THROUGH CENTRAL NEW YORK STATE TO WEST-CENTRAL PENNSYLVANIA THEN DOWN THROUGH THE OHIO VALLEY. AN UPPER AIR ANALYSIS INDICATED A STRONG CYCLONICALLY CURVED 300 MB JET OVER THE GREAT LAKES AND INTO NEW ENGLAND. A CLOSED MIDLEVEL LOW WAS OVER SOUTHEAST CANADA WHILE A RIDGE WAS IN THE NORTHERN PLAINS. SYNOPTICALLY, A STRONG UPPER-LEVEL TROUGH WILL BE MIGRATING FROM THE GREAT LAKES REGION TO THE NORTHEAST THROUGH TODAY. THE CYCLONIC FLOW BEHIND THE SURFACE COLD FRONT WILL ALLOW FOR INCREASING CAA WITH TIME. THE MAIN FOCUS TODAY IS THE PASSAGE OF A STRONG BUT MAINLY MOISTURE STARVED COLD FRONT. THIS BOUNDARY IS FORECAST TO CROSS THE CWA FROM LATER THIS MORNING TO ABOUT THE EARLY AFTERNOON HOURS FROM WEST TO EAST. A DECENT AMOUNT OF CONVECTION FORMED AHEAD OF THE BOUNDARY EARLY LAST EVENING FROM THE EASTERN GREAT LAKES TO THE UPPER OHIO VALLEY, AS A RIBBON OF DEEPER MOISTURE COINCIDED WITH A RATHER IMPRESSIVE MIDLEVEL WIND MAX AND AN AXIS OF MLCAPE. THE BULK OF THIS IS LIFTING UP TO OUR NORTH, WEAKENING AND HEADED INTO NEW ENGLAND, HOWEVER SOME MODEST MIDLEVEL FLOW IS FORECAST TO CROSS OUR AREA. THIS MAY TEND TO KEEP AT LEAST SOME ELEVATED INSTABILITY ACROSS THE CWA ESPECIALLY NORTHEASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY. THE QUESTION IS WHETHER THE CONVECTION CAN MAKE IT INTO OUR AREA THIS MORNING OR REDEVELOP. THE GFS APPEARS TO BE A BIT SLOW WITH THE BACK EDGE OF THE CONVECTION. THE 12Z/07 SPC 4KM WRF HAD A GOOD HANDLE ON THE TIMING AND AREAL EVOLUTION OF THIS CONVECTION LAST EVENING AND TRENDS SO FAR EARLY THIS MORNING, THEREFORE AM INCLINED TO FOLLOW THIS A BIT CLOSER. THEREFORE, WE WILL JUST STICK WITH MAINLY SOME SLIGHT CHC TO LOW END CHC POPS ACROSS THE NORTHERN AREAS THIS MORNING TO EARLY AFTERNOON. SOME ACTIVITY HAS BEEN REDEVELOPING ACROSS SOUTH-CENTRAL PENNSYLVANIA SO THIS WILL BE MONITORED AND SOME POP ADJUSTMENTS MAY BE NEEDED WITH THE 09Z UPDATE. OTHERWISE, MAINLY MID TO HIGH LEVEL CLOUDS ALONG AND AHEAD OF THE COLD FRONT /PROBABLY BE ABLE TO ADVECT OR DEVELOP SOME CUMULUS AS WELL/, THEN FAIRLY QUICK CLEARING BEHIND THE COLD FRONT AS MUCH DRIER AIR ADVECTS IN ALONG WITH DEVELOPING CAA AND DOWNSLOPING FLOW. SOME GUSTINESS IN THE SOUTHERLY FLOW AHEAD OF THE COLD FRONT, THEN ADDITIONAL GUSTY WINDS BEHIND THE COLD FRONT AS THE LOW-LEVEL LAPSE RATES STEEPEN WITH THE DEVELOPING CAA ABOVE SURFACE HEATING. THE FORECAST SOUNDINGS INDICATE THAT THE WINDS INCREASE TO NEARLY 30 KNOTS AT THE TOP OF THE DEEPENING BOUNDARY LAYER. THIS WOULD TRANSLATE TO 30 TO 35 MPH WIND GUSTS BEHIND THE FRONT. THIS WILL PROBABLY BE DELAYED ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES AS THE FRONT ARRIVES HERE LATER. OVERALL, THE SITUATION LOOKS TO BE BELOW WIND ADVISORY CRITERIA. THE WINDS COMBINED WITH THE DRIER AIR SURGING IN BEHIND THE FRONT WILL LEAD TO FIRE WEATHER CONCERNS, THEREFORE SEE THE FIRE WEATHER SECTION BELOW FOR MORE DETAILS. AS FOR TEMPERATURES, GIVEN THE MILD START ACROSS THE BULK OF THE CWA UNDER WAA AHEAD OF THE COLD FRONT, LEANED TOWARD THE WARMER NAM MOS. THIS POINTS TOWARD WARMER TEMPERATURES ESPECIALLY ACROSS THE EASTERN AND SOUTHERN ZONES AS THE CAA WILL ARRIVE HERE IN EARNEST LATER IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN AREA OF LOW PRESSURE IS FORECAST TO BE NEAR NORTHERN NEW ENGLAND AS A CLOSED MIDLEVEL LOW SETS UP SHOP IN THAT VICINITY. THE ASSOCIATED LARGE TROUGH ENCOMPASSING THE NORTHEAST AND MID ATLANTIC STATES WILL RESULT IN A CYCLONIC FLOW BRINGING COOLER AIR TO THE REGION. THE NORTHWESTERLY FLOW OF THIS COOL AND DRY AIRMASS WILL ALLOW FOR LITTLE CLOUDS TO OCCUR TONIGHT. THE EXCEPTION SHOULD BE THE NORTHWESTERN ZONES WHERE THE CAA, COMBINED WITH THE FLOW OFF THE WARM EASTERN GREAT LAKES, CYCLONIC FLOW AND MOISTURE BECOMING TRAPPED UNDER AN INVERSION TO TOSS STRATOCUMULUS SOUTHEASTWARD. THEREFORE WE WILL CARRY MORE CLOUDS THERE THROUGH THE NIGHT AND ALSO DURING THURSDAY. THE WIND TONIGHT SHOULD DECOUPLE AT LEAST SOME, ALTHOUGH A COMPLETE DECOUPLING IS NOT ANTICIPATED GIVEN THE TIGHTENED PRESSURE GRADIENT AND CAA. THEREFORE, WE WILL GRADUALLY THROTTLE BACK ON THE WINDS. A FEW SHOWERS/SPRINKLES CANNOT BE RULED OUT MAINLY THURSDAY AFTERNOON THROUGH FRIDAY, THEREFORE SLIGHT CHC POPS WILL BE MAINTAINED AT TIMES FOR THE NORTHWESTERN ZONES. WE ARE SEEING A LITTLE INSTABILITY IN THE FORECAST SOUNDINGS THURSDAY AFTERNOON FARTHER SOUTH, THEREFORE CAA STRATOCUMULUS/CUMULUS WILL PROBABLY DEVELOP BUT POTENTIALLY FIGHT THE DOWNSLOPING FLOW /AS OF NOW WE ARE NOT ANTICIPATING ANY SPRINKLES OR BRIEF SHOWERS TO BE ABLE TO DEVELOP FROM THIS/. WE TRIED TO INDICATE THIS IN THE SKY COVER GRIDS FROM NORTHWEST TO SOUTHEAST. FOR FRIDAY, THE PRESSURE GRADIENT IS FORECAST TO GRADUALLY RELAX THEREFORE THE WINDS SHOULD NOT BE AS GUSTY COMPARED TO TODAY AND THURSDAY. AS FOR TEMPERATURES, WE GENERALLY UTILIZED AN EVENLY WEIGHTED BLEND OF THE NAM/GFS MOS BUT MADE A FEW ADJUSTMENTS FOR LOCAL AFFECTS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THIS TIME FRAME IS COMPRISED OF SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, LOW TEMPERATURES MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE HAVE SHOWERS AND THUNDERSTORMS CHCS ARRIVING DURING THE DAY ON SUNDAY. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WITH RESPECT TO THUNDER WITH THE GFS MORE BULLISH OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PRECIPITATION EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE MODEL RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHOWER SLIGHT CHC/CHC WERE ADDED ATTM. TEMPERATURE-WISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH READINGS PRETTY CLOSE TO AVERAGE. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE COLD FRONT IS SLOWER IN ARRIVING. OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY. HOWEVER, WE DID BLEND IN A SMALL PERCENTAGE OF THE 00Z MOSGUIDE TO SOME FIELDS TO INTRODUCE A LITTLE BIT OF NEW GUIDANCE INTO THE FORECAST. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 08Z-14Z...VFR WITH A MARGINAL LLWS CONDITION THROUGH ABOUT 11Z. OTHERWISE A LINE OF SCT ELEVATED CONVECTION WILL PUSH EWD ACROSS THE FCST AREA. MOST OF IT SHOULD BE A 20 MINUTE SHOWER OR SPRINKLE HOWEVER...ISOLATED THUNDER IS EXPECTED. THUNDER PARAMETERS LOOK SIGNIFICANT AND THE LINE "MAY" REIGNITE AS IT CROSSES THE POCONOS AND NORTHERN TWO THIRDS OF NJ WITH ISOLATED GUST 35 KTS IN A 20 MINUTE OR LESS MVFR CONDITION ISOLATED TRW+. AFTER 14Z TODAY...VFR QUICKLY BECOMING SKC WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... THURSDAY AND FRIDAY: VFR. GUSTY WNW WINDS 20-28 KTS DAYLIGHT HOURS DIMINISH AT NIGHT. CYCLONIC FLOW DOMINATES OUR WEATHER THROUGH FRIDAY WITH A SECONDARY WEAK COOL FRONTAL PASSAGE THURSDAY AFTERNOON OR EVENING. DIURNALLY HEAT DRIVEN CONSIDERABLE CLOUD COVER 3500 TO 5500 FT THURSDAY AND FRIDAY DAYLIGHT HOURS TENDS TO CLEAR AT NIGHT. MOST OF THE CLOUDINESS EASTERN PA AND NORTHERN TWO THIRDS OF NJ. SCT SHOWERS OR SPRINKLES POSSIBLE THURSDAY AFTERNOON POCONOS AND NORTHERN NJ WITH SHORT WAVE ROTATING SEWD THRU THE AREA AND A WEAK WIND SHIFT. SATURDAY...VFR LIGHT WIND AND HIGH PRESSURE OVERHEAD. SUNDAY...CONDITIONS MAY DEGRADE IN POTENTIAL LOW PRESSURE PASSAGE WITH MVFR CONDS IN SHOWERS. && .MARINE... EXTENDING SCA THROUGH 00Z THU FOR NEAR SHORE /WITHIN 5 MI OF THE LAND/ GUSTS 25-30 KTS AFTER THE MORNING CFP. TONIGHT...WINDS MAY CONTINUE OCCASIONALLY GUSTING 25 KTS VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD FROM THE COAST. THE EXCEPTION FOR TONIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY AND FRIDAY...NW WIND GUSTS 20-25 KNOTS. MIGHT BE A SECONDARY WEAK CFP LATE IN THE DAY THAT ENHANCES WIND TRANSFER INTO THU NIGHT. SATURDAY...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS. SUNDAY...DEGRADING CONDITIONS IN POTENTIAL SHOWERS AND LOW PRESSURE. && .FIRE WEATHER... FOLLOWING THE PASSAGE OF A COLD FRONT LATER THIS MORNING AND EARLY THIS AFTERNOON, MUCH DRIER AIR AND INCREASING WINDS WILL ARRIVE ACROSS THE AREA. THIS WILL ALLOW THE DEW POINTS TO TUMBLE AS WINDS INCREASE FROM THE WEST. MODEL FORECAST SOUNDINGS SUGGEST MIXING FROM 850 MB COULD DROP DEW POINTS INTO THE MID AND UPPER 40S THIS AFTERNOON. MODEL FORECAST SOUNDINGS ALSO SHOW THAT ABOUT 30 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE DEEPENING BOUNDARY LAYER THIS AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS OF 30 TO 35 MPH, MAINLY FROM LATE MORNING ON. A POSSIBLE FLY IN THE OINTMENT IS THAT IF THE COLD FRONT IS SLOWER IN CLEARING THE AREA, THEN THE TIGHTENING PRESSURE GRADIENT AND CAA WOULD BE DELAYED RESULTING IN A DELAY OF THE GUSTY WINDS AND DRIER AIR. GIVEN THE RATHER DRY CONDITIONS ACROSS THE REGION AND FORECAST WINDS AND RELATIVE HUMIDITY VALUES, THE RED FLAG WARNING WILL BE MAINTAINED AS IS FOR NOW. DEPENDING THOUGH ON RELATIVE HUMIDITY AND WIND TRENDS, SOME EXPANSION OF THE WARNING MAY BE NEEDED LATER ESPECIALLY FOR THE FAR SOUTHERN AREAS. WE ARE ANTICIPATING GUSTY WINDS ON THURSDAY, HOWEVER WITH COOLER TEMPERATURES THE RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER RELATED HEADLINES. A MENTION WILL BE INCLUDED ONLY IN THE FIRE WEATHER FORECAST FOR NOW. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR PAZ060-061-067>071. NJ...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR NJZ009-010-012>027. DE...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR DEZ001-002. MD...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR MDZ008-012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...GORSE NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...GIGI/GORSE AVIATION...DRAG MARINE...DRAG FIRE WEATHER...HAYES/GORSE CLIMATE...DRAG 000 FXUS61 KPBZ 080655 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 255 AM EDT WED SEP 8 2010 .SYNOPSIS... WEAK SURFACE TROUGHING WILL LINGER THROUGH THURSDAY...FOLLOWING THIS MORNINGS FRONTAL PASSAGE. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... SURFACE ANALYSIS AT 3 AM DEPICTS FRONT EXTENDING FROM NEAR FKL TO JUST WEST OF PIT TO NEAR ZZV. AS THE FRONT MOVES EAST EARLY THIS MORNING...SO WILL THE REMAINING SHOWERS. AFTER A PERIOD OF MAINLY SUNNY SKIES THIS MORNING...STRATOCU SHOULD DEVELOP IN A MOIST LAYER AROUND 850MB. TEMPS WILL BE ABOUT 15 TO 20 DEGREES COOLER TODAY THAN ON TUESDAY...WITH WINDS STILL A LITTLE GUSTY. BASED ON FORECAST RH AND WINDS...SOUTHEAST MOUNTAINS WILL HAVE THE BEST FIRE WEATHER POTENTIAL TODAY. BUT AGAIN THIS AREA DOES NOT MEET CRITERIA FOR A RED FLAG...BASED ON CURRENT FORECAST. DEWPOINT TRENDS WILL NEED TO BE MONITORED LATER THIS MORNING INTO EARLY AFTERNOON. IF DEWPOINTS DO NOT COME UP AS EXPECTED...THE FIRE HAZARD WILL INCREASE. THEREFORE...THIS POTENTIAL WILL NEED TO BE MONITORED AGAIN THIS AFTERNOON. EXPECT SOME STRATUS TO HOLD ON INTO TONIGHT...BUT MOST DIMINISH WITH THE LOSS OF DIURNAL HEATING. WITH THE COOL NORTHWEST FLOW ACROSS THE LAKES ANTICIPATE SOME LAKE ENHANCED SHOWERS THIS AFTERNOON THROUGH TONIGHT NORTH. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... WITH SURFACE TROUGHING CONTINUING...ALONG WITH A RELATIVELY COOL NORTHWEST FLOW...STRATOCU DEVELOPMENT IS A GOOD BET THURSDAY...ESPECIALLY NORTH. IN ADDITION SPOTTY LAKE ENHANCED SHOWERS WILL BE POSSIBLE NORTHEAST THURSDAY. AS THE SURFACE RIDGE BUILDS INTO FRIDAY...CLOUD DEVELOPMENT WILL BE MINIMAL. TEMPS SHOULD RUN 5 TO 10 BELOW NORMAL DURING THIS PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SKIES ARE CLEARING IN THE WAKE OF A COLD FRONT...WITH ALL AREAS HAVING FEW IF ANY CLOUDS THROUGH MID MORNING. NW FLOW WILL INCREASE BY THIS AFTN...ALLOWING FOR A STRATOCUMULUS DECK TO DEVELOP FROM PIT NORTHWARD. WILL USE LOW END VFR BROKEN CIGS WITH THIS DECK...WITH SCATTERED CLOUDS SOUTH OF A LBE/HLG LINE. AN ISOLATED SPRINKLE OR SHOWER IS ALSO POSSIBLE FOR FKL/DUJ THIS AFTN. CLOUDS WILL GRADUALLY ERODE TNGT AS HIGH PRESSURE BEGINS TO BUILD IN. VFR WILL PREVAIL FOR THURSDAY INTO SATURDAY UNDER THE HIGH...WITH A FRONTAL SYSTEM PROGGED TO AFFECT THE AREA FOR LATE SATURDAY THROUGH SUNDAY...BRINGING AREAS OF RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPBZ 080428 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1227 AM EDT WED SEP 8 2010 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING SCATTERED THUNDERSTORMS. THIS FRONT WILL BRING MUCH COOLER TEMPERATURES INTO LATE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... THE COLD FRONT CONTINUES TO MOVE ACROSS THE REGION. THUNDERSTORM COVERAGE HAS BEEN SCATTERED ALONG THE FRONT. BEHIND THE FRONT MUCH COOLER AIR WILL ARRIVE BY MORNING WITH LOWS IN THE MID TO UPPER 50S. WITH NORTHWEST WINDS WEDNESDAY EXPECT SOME CLOUDS ACROSS THE NORTHERN TIER OFF THE LAKES AND POSSIBLY A SPRINKLE. TEMPERATURES WILL BE MUCH COOLER WITH UPPER 60S NORTH UNDER CLOUDS TO MID 70S SOUTH WHERE SUNSHINE PREVAILS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL LOW WILL SPIN ACROSS THE NORTHERN LAKES TO NEW ENGLAND THROUGH THE PERIOD WITH NORTHWEST FLOW TO DOMINATE WEATHER. EXPECT CLOUDS OFF OF THE LAKES TO BE ACROSS THE NORTH IN A DIURNAL FASHION WITH A SPRINKLE OR TWO POSSIBLE FAR NORTH. OTHERWISE SEASONABLY COOL THROUGH THE PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... A COLD FRONT WILL CONTINUE TO CROSS WESTERN PA TO WESTERN MD...WITH A BROKEN LINE OF SHWRS/TSTMS. INTENSITY OF THE STORMS IS DECREASING...WITH MVFR POSSIBLE AT DUJ/LBE IN THE NEXT COUPLE OF HOURS. THE FRONT WILL MOVE EAST OVERNIGHT...WITH CLOUDS SCATTERING OUT. STRONG NW FLOW DEVELOPING BY 15Z-18Z WEDNESDAY WILL RESULT IN STRATOCUMULUS DECK ACROSS AREAS FROM PIT/LBE NORTHWARD...WITH AN ISOLATED SHWR POSSIBLE. HIGH PRESSURE BUILDS IN FOR THURSDAY AND FRIDAY FOR VFR CONDITIONS. A FRONTAL SYSTEM WILL AFFECT THE AREA SATURDAY WITH LINGERING SHOWERS POSSIBLE INTO SUNDAY...WITH AREAS OF MVFR. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 080342 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1142 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT, AND THEN CROSS THE AREA WEDNESDAY MORNING. BEHIND THE FRONT, COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILDING INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY, FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 02Z, A COLD FRONT WAS CROSSING THE EASTERN GREAT LAKES REGION AND THEN DOWN ACROSS THE OHIO VALLEY. A DECENT AMOUNT OF CONVECTION FORMED AHEAD OF THE FRONT WITH SOME IMPRESSIVE FORWARD MOTIONS NOTED. THIS ACTIVITY APPEARS TO HAVE BEEN ENHANCED BY AN IMPRESSIVE MID LEVEL WIND MAX OF ABOUT 60 KNOTS. A RIBBON OF DEEPER MOISTURE IS ADVECTING AHEAD OF THE FRONT, COMBINED WITH ENOUGH INSTABILITY, HAS HELPED FOCUS THE CONVECTION. THERE ARE SOME DIFFERENCES IN THE MODEL GUIDANCE REGARDING THE EVOLUTION OF THIS ACTIVITY THROUGH THE OVERNIGHT. SOME WEAKEN THE SOUTHERN FLANK OF THE CONVECTION AND KEEP IT TO OUR NORTH WHILE SOME OTHERS MAINTAIN IT INTO OUR ACROSS MOST OF OUR CWA. THERE IS AT LEAST SOME ELEVATED INSTABILITY FORECAST TO LINGER THROUGH THE NIGHT SO THIS COULD BE WHAT HELPS MAINTAIN SOME OF THE ACTIVITY INTO AT LEAST SOME OF OUR CWA LATE TONIGHT. INTERESTINGLY ENOUGH, THE SPC 4KM WRF SIMULATED REFLECTIVITY DID WELL WITH THE TIMING AND COVERAGE OF THE CONVECTION FROM WESTERN NEW YORK TO NORTHEAST OHIO. THIS MODEL WEAKENS THE ACTIVITY WITH THE BULK OF IT PASSING TO OUR NORTH, CLOSER TO THE STRONGER MIDLEVEL FLOW AND FRONTAL FORCING. GIVEN THE UNCERTAINTY STILL, WE WILL MAINTAIN THE POPS AS PREVIOUSLY NOTED AND CONTINUE TO MONITOR RADAR TRENDS. THE HOURLY GRIDS WERE ADJUSTED WITH THE 02Z OBSERVATIONS AND THE LAV/LAMP GUIDANCE WAS BLENDED IN TO HELP CAPTURE SOME OF THE TRENDS THUS FAR. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. EARLY THIS MORNING THROUGH 08Z...VFR WITH A MARGINAL LLWS CONDITION CONTINUED IN THE TAFS. PLEASE SEE TAFS FOR DETAILS. 08Z-14Z...A LINE OF SCT ELEVATED CONVECTION WILL PUSH EWD ACROSS THE FCST AREA. MOST OF IT SHOULD BE A 20 MINUTE SHOWER OR SPRINKLE HOWEVER...ISOLATED THUNDER IS EXPECTED. THUNDER PARAMETERS LOOK SIGNIFICANT AND THE LINE MAY REIGNITE AS IT CROSSES THE POCONOS AND NORTHERN NJ WITH ISOLATED GUST 35 KTS IN A 20 MINUTE OR LESS MVFR TRW+. AFTER 14Z WED...VFR QUICKLY BECOMING SKC WITH W WIND GUSTING 25-33KTS. AFTER 00Z THU...WINDS DIMINISH RAPIDLY WITH VFR CONDS EXCEPT KPHL AND KACY WHERE NW GUSTS 20 KTS MAY PERSIST INTO THE NIGHT WITH DECENT CAA. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... SCA HEADLINE CONTD AS IS EARLY THIS MORNING. MORE THAN LIKELY IN THE 4AM ISSUANCE WILL EXTEND SCA THROUGH 06Z THU FOR NEAR SHORE /WITHIN 5 MI OF THE LAND/ GUSTS 25-30 KTS AFTER THE MORNING CFP AND THEN UPCOMING WEDNESDAY NIGHT VIRTUALLY ALL WATERS WITH CAA OVER WARM SST...TRANSFER EXTENDS OUTWARD AND GUSTS SHOULD BE OCCASIONALLY 25 KTS. THE EXCEPTION FOR WED NIGHT MIGHT BE THE UPPER PORTION OF DELAWARE BAY. THURSDAY...NW WIND GUSTS 20-25 KNOTS AND THATS FOR FUTURE CONSIDERATION ON EXTENDING SCA INTO LATE THURSDAY. FRIDAY AND BEYOND...HIGH PRESSURE WILL THEN BUILD INTO THE AREA BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... THE FIRE WEATHER WATCH WAS CONVERTED TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED BUT WEDNESDAY IS FORECAST TO EXCEED. POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ431- 450>455. && $$ SYNOPSIS...GORSE/HAYES NEAR TERM...GORSE SHORT TERM...HAYES LONG TERM...GIGI AVIATION...DRAG/GIGI/RPW 1142P MARINE...DRAG/GIGI/RPW 1142P FIRE WEATHER... CLIMATE...1142P 000 FXUS61 KPHI 080245 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1045 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT, AND THEN CROSS THE AREA WEDNESDAY MORNING. BEHIND THE FRONT, COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILDING INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL THEN CROSS THE AREA SUNDAY, FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 02Z, A COLD FRONT WAS CROSSING THE EASTERN GREAT LAKES REGION AND THEN DOWN ACROSS THE OHIO VALLEY. A DECENT AMOUNT OF CONVECTION FORMED AHEAD OF THE FRONT WITH SOME IMPRESSIVE FORWARD MOTIONS NOTED. THIS ACTIVITY APPEARS TO HAVE BEEN ENHANCED BY AN IMPRESSIVE MIDLEVEL WIND MAX OF ABOUT 60 KNOTS. A RIBBON OF DEEPER MOISTURE IS ADVECTING AHEAD OF THE FRONT, COMBINED WITH ENOUGH INSTABILITY, HAS HELPED FOCUS THE CONVECTION. THERE ARE SOME DIFFERENCES IN THE MODEL GUIDANCE REGARDING THE EVOLUTION OF THIS ACTIVITY THROUGH THE OVERNIGHT. SOME WEAKEN THE SOUTHERN FLANK OF THE CONVECTION AND KEEP IT TO OUR NORTH WHILE SOME OTHERS MAINTAIN IT INTO OUR ACROSS MOST OF OUR CWA. THERE IS AT LEAST SOME ELEVATED INSTABILITY FORECAST TO LINGER THROUGH THE NIGHT SO THIS COULD BE WHAT HELPS MAINTAIN SOME OF THE ACTIVITY INTO AT LEAST SOME OF OUR CWA LATE TONIGHT. INTERESTINGLY ENOUGH, THE SPC 4KM WRF SIMULATED REFLECTIVITY DID WELL WITH THE TIMING AND COVERAGE OF THE CONVECTION FROM WESTERN NEW YORK TO NORTHEAST OHIO. THIS MODEL WEAKENS THE ACTIVITY WITH THE BULK OF IT PASSING TO OUR NORTH, CLOSER TO THE STRONGER MIDLEVEL FLOW AND FRONTAL FORCING. GIVEN THE UNCERTAINTY STILL, WE WILL MAINTAIN THE POPS AS PREVIOUSLY NOTED AND CONTINUE TO MONITOR RADAR TRENDS. THE HOURLY GRIDS WERE ADJUSTED WITH THE 02Z OBSERVATIONS AND THE LAV/LAMP GUIDANCE WAS BLENDED IN TO HELP CAPTURE SOME OF THE TRENDS THUS FAR. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A VFR FORECAST WAS ISSUED WITH THE 00Z TAFS. LINE OF CONVECTIVE SHRAS AND TSTMS IS FORECAST TO WEAKEN/DISPERSE AS IT APPROACHES OUR CWA OVERNIGHT. NOT CONFIDENT THAT THEY MAKE IT TO ANY SPECIFIC TERMINAL AND IF THEY DO ANY PCPN REDUCTIONS TO VSBYS AND CIGS MAY VERY WELL STAY IN THE VFR CATEGORY. IF WE ARE WRONG MOST LIKELY PLACES IT WOULD BE KABE AND KRDG AND THEIR ARRIVAL WOULD NOT BE UNTIL AFTER 06Z. OTHERWISE FOR THE OVERNIGHT WE ARE FORECASTING RESIDUAL MID AND HIGH LEVEL CLOUDS TO OVERSPREAD THE TERMINALS. THE LATEST 18Z GUIDANCE WEAKENED THE LLJ A BIT AND WE REDUCED THE TIME OF LLWS POTENTIAL FROM THE KPHL METRO AREA AIRPORTS SEWD. THE LLJ WINDS ARE FORECAST TO REMAIN THE STRONGEST, THE LONGEST AT KABE AND KRDG. THE COLD FRONT SHOULD MOVE THRU THE TERMINALS FROM NW TO SE APPROXIMATELY 11Z TIL 14Z AND WINDS SHOULD INCREASE FROM THE WEST FAIRLY RAPIDLY POST COLD FRONTAL. NOT MUCH MOISTURE WILL BE LEFT IN ITS WAKE AND ONLY A FEW VERY HIGH BASED CUMULUS CLOUDS ARE FORECAST. IT WILL BE WINDY AND PEAK WIND GUSTS SHOULD AVERAGE AROUND 30KTS ESPECIALLY AT THE WINDIER TERMINALS LIKE KPHL. WINDS SHOULD DECREASE RAPIDLY WED EVE. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... WE ARE GOING TO EXTEND THE SCA TO ALL OF THE COASTAL WATERS EXCEPT FOR UPPER DELAWARE BAY. WINDS AND SEAS CONTINUE TO INCREASE AND WITH STRONGER WINDS FORECAST ALOFT OVERNIGHT AND LESS OF AN AIR/WATER DIFFERENTIAL DO NOT SEE THIS TREND REVERSING. WILL LEAVE UPPER DELAWARE BAY OUT FOR NOW AS THERE IS SOME DECOUPLING OCCURRING OVER THE LAND AND THE WIDTH OF THAT PART OF THE BAY MAY NOT BE WIDE ENOUGH TO BRING ENOUGH MIXED WIND BAYWARD. ONCE THE FRONT CROSSES OUR AREA WEDNESDAY, WINDS WILL SHIFT TO THE WEST. THE WIND SHIFT WILL KNOCK DOWN THE SEAS ALSO. THE HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE AREA, BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... THE FIRE WEATHER WATCH WAS CONVERTED TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED, POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ431- 450>455. && $$ SYNOPSIS...GORSE/HAYES NEAR TERM...GORSE SHORT TERM...HAYES LONG TERM...GIGI AVIATION...GIGI/RPW MARINE...GIGI/RPW FIRE WEATHER...HAYES CLIMATE...DRAG 000 FXUS61 KLWX 080151 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 951 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE COAST THROUGH TONIGHT. A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO WEDNESDAY... BRINGING BREEZY CONDITIONS. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND PERSIST INTO THE WEEKEND. ANOTHER COLD FRONT WILL IMPACT THE REGION SUNDAY...WHICH WILL BE FOLLOWED BY MORE HIGH PRESSURE. && .NEAR TERM /THROUGH WEDNESDAY/... COASTAL FLOOD ADVISORY ISSUED FOR MINOR TIDAL FLOODING ALONG OUR TIDAL SHORELINE. NEW MOON IS SEEING TO HIGH ASTRONOMICAL TIDES. THAT COMBINED WITH S WINDS CONTINUING TO PUSH WATER UP THE BAY AND POTOMAC... AND THE FACT THAT WED MORNINGS HIGH TIDE IS THE HIGHER OF THE TWO DAILY ASTRONOMICAL TIDES SHOULD SEE TO HIGH TIDES WED MORN THAT ARE SLIGHTLY ABOVE WHAT THEY WERE THIS EVENING. AM EXPECTING AT OR SLIGHTLY ABOVE CRITERIA FOR MINOR TIDAL FLOODING AT ALL OF OUR TIDAL GAGES ON THE POTOMAC AND BAY....INCLUDING DC ALEXANDRIA ANNAPOLIS AND BALTIMORE. HIPRES WILL CONTINUE TO PUSH OFF THE MID-ATLANTIC COAST TNGT AS A COLD FRONT OVER THE MIDWEST PUSHES THRU THE OH VLY THIS EVE AND ACROSS THE CENTRAL APPALACHIANS LATE TONIGHT. THE FRONT SHOULD BEGIN TO ENTER THE WRN SLOPES OF THE ALLEGHENY FRONT AROUND DAYBREAK WED MRNG. THE RECENT LOCAL MODELS AND 18Z NAM AND GFS PAINT AN INCONSISTENT PICTURE WHETHER THE THUNDERSTORMS OVER EASTERN OH AND WESTERN PA WILL MAKE IT INTO OUR CWA. THE HRRR/WRF GFS NAM AND RUC SAY NO...WHILE A FEW OF THE LATEST LOCAL WRFS SAY THEY MAY. DOWNSLOPING IN THE MIDLEVELS AND DECREASING INSTAB AHEAD OF THE FRONT WITH THE DIURNAL MIN SHOULD HELP TO KEEP THEM FROM MOVING THRU. FOR NOW WILL MAINTAIN THE CHANCES IN OUR MOUNTAIN WEST AND WILL SEE HOW THE NEXT FEW HOURS GO. THE FRONT WILL CROSS THE I-95 CORRIDOR IN THE MRNG...AND PUSH THRU LOWER SRN MD BY THE ERY AFTN. AFTER AN INCREASE IN MID TO UPPER CLOUDS ASSOCIATED WITH THE FROPA IN THE MRNG...SKIES WILL CLEAR OUT BEHIND THE FRONT AS THE ENTIRE COLUMN QUICKLY DRIES OUT. GUSTY WESTERLY WINDS ARE EXPECTED TO INCREASE TO 15-20 MPH WITH GUSTS TO 30 MPH POSSIBLE DURING THE AFTN. SEE FIRE SECTION FOR DISCUSSION OF FIRE THREAT ON WED. DAYTIME HIGHS WED WILL RANGE FROM THE 70S ACROSS THE RIDGE TOPS TO MU80S EAST OF THE BLUE RIDGE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT IN THE WAKE OF THE DAYTIME FROPA WITH DOWNSLOPING WLY FLOW ENSURING DRY AND CLEAR CONDITIONS /ANY SKY COVER WOULD BE HIGH CLOUDS/. COLD AIR ADVECTION TO PREVENT DECOUPLING...MIN TEMPS AROUND 60F EAST OF I-95...LOW TO MID 50S INLAND...LOW 40S FOR HIGH ELEVATIONS OUT WEST. THURSDAY THROUGH FRIDAY NIGHT...UPPER LOW DRIFTS EAST ACROSS NEW ENGLAND AS A RIDGE AMPLIFIES AS IT BUILDS EAST ACROSS THE MIDWEST. THIS WILL MAINTAIN DRY NWLY FLOW WITH SUNNY/CLEAR CONDITIONS MAX TEMPS LIMITED TO UPPER 70S /JUST BELOW NORMAL/. MIN TEMPS A FEW DEGREES BELOW NORMAL BOTH NIGHTS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A COLD FRONT ASSOCIATED WITH A LOW OVER NRN ONTARIO LOOKS TO IMPACT THE MID ATLANTIC IN THE SUNDAY TIMEFRAME. WENT WITH A BLEND OF THE QUICKER GFS AND SLOWER ECMWF FOR A SUNDAY AFTERNOON/EVENING FROPA ATTM. REMNANT MOISTURE FROM HERMINE SHOULD BE PICKED UP FROM THIS SYSTEM...SO HOPEFULLY THIS WILL BE A MORE WIDESPREAD RAIN EVENT...THOUGH A WEST TO EAST FROPA WOULD SUGGEST SCATTERING PRECIP AS IT PASSES THE APPALACHIANS. MORE HIGH PRESSURE POST FROPA. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS TNGT AND WED. S-SW WINDS WILL CONTINUE TO DIMINISH TONIGHT. MTN AND DCA WILL LIKELY HOLD ON THE LONGEST BEING CLOSE TO THE WATER. A COLD FRONT WILL MOVE THRU THE TERMINALS WED MRNG. FROPA WILL BE MARKED BY A WINDSHIFT FROM THE WEST. DURING THE LATE MRNG INTO THE AFTN...SUSTAINED WINDS WILL INCREASE TO AROUND 15 KT...WITH GUSTS 20-25 KT POSSIBLE. POST FROPA WLY/NWLY FLOW WITH VFR CONDS WED NIGHT INTO THE WEEKEND. NEXT COLD FRONT IN THE SUNDAY TIMEFRAME. && .MARINE... WINDS ARE SLACKENING OUTSIDE OF THE MAIN CHANNEL OF THE BAY S OF POOLES AND THE LOWERMOST PART OF THE POTOMAC. WILL ALLOW SCA TO EXPIRE AT 02Z FOR THE SLACKENING AREAS WHILE CONTINUING WITH THE EXISTING SCA FOR THE BAY AND LOWR POTOMAC THRU TNT. A COLD FRONT WILL MOVE THRU THE WATERS LATE WED MRNG INTO THE ERY AFTN. WIDESPREAD GUSTS OF 20 KT EXPECTED BEHIND THE FRONT. EXTENDED SCA THROUGH WEDNESDAY NIGHT FOR THE MD BAY/SRN TIDAL POTOMAC AND EASTERN TRIBUTARIES /NOT PATAPSCO OR PAX RIVER/ WITH POST FROPA WLY/NWLY COOL FLOW MIXING DOWN OVER THE WARM WATER. NEAR SCA NWLY FLOW THEN PERSISTS INTO THE WEEKEND WITH AND UPPER LOW OVER NEW ENGLAND...SCA/S MORE LIKELY IF WIND IS ABLE TO VEER TO NLY AND CHANNEL DOWN THE BAY. && .FIRE WEATHER... EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE...GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. PLEASE NOTE- BURNING BAN FOR ERN WV PANHANDLE WENT INTO EFFECT THIS MRNG AND WILL CONTINUE UNTIL FURTHER NOTICE. A COLD FRONT WILL MOVE THRU THE REGION LATE TNGT INTO WED. BREEZY AND DRY CONDITIONS ARE EXPECTED BEHIND THE FRONT ON WED. RED FLAG CONDITIONS ARE POSSIBLE ON WED WITH SUSTAINED WINDS APPROACHING 20 MPH AND MIN AFTN RH VALUES BETWEEN 25-30 PERCENT COMBINED WITH THE ALREADY LOW FUEL MOISTURE. AFTER TALKING TO STATE FIRE OFFICIALS...A A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MOST OF THE CWFA...WITH THE EXCLUSION OF THE NRN PIEDMONT AND CENTRAL FOOTHILLS IN VA /WHERE WINDS WILL LIGHTER/. WILL COORDINATE WITH STATE FIRE OFFICIALS IN THE MRNG WHEN WRNG HEADLINE DECISIONS ARE MADE. NWLY FLOW WILL CONTINUE FOR THURSDAY AND FRIDAY...MAINTAINING AN ENHANCED FIRE WX THREAT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR DCZ001. COASTAL FLOOD ADVISORY FROM 1 AM TO 11 AM EDT WEDNESDAY FOR DCZ001. MD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR MDZ003>007-009>011-013-014-016>018-501-502. COASTAL FLOOD ADVISORY FROM 1 AM TO 11 AM EDT WEDNESDAY FOR MDZ007-011-013-014-016>018. VA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR VAZ021-025>031-038>040-042-051>054-501-502. COASTAL FLOOD ADVISORY FROM 1 AM TO 11 AM EDT WEDNESDAY FOR VAZ052>055-057. WV...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR WVZ050>055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ531>534- 537-539>541-543. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ530- 535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM TO 8 PM EDT WEDNESDAY FOR ANZ535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO 6 AM EDT THURSDAY FOR ANZ530. && $$ SYNOPSIS...BAJ NEAR TERM...JRK SHORT TERM...BAJ LONG TERM...BAJ AVIATION...BAJ/JRK MARINE...BAJ/JRK FIRE WEATHER... 000 FXUS61 KAKQ 080150 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 950 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION WEDNESDAY AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING BACK INTO THE AREA THURSDAY AND FRIDAY. THE HIGH WILL SLIDE OFF THE COAST OVER THE WEEKEND...WITH ANOTHER COLD FRONT EXPECTED TO CROSS THE MID ATLANTIC STATES SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SFC HIGH PRESSURE NOW CENTERED WELL OFF THE NC COAST...WITH A DEEP S TO SSW FLOW OVER THE CWA. WHILE WIND SPEEDS OVERNIGHT WILL GNLY BE ON THE ORDER OF 5-10 MPH...LOOKS LIKE ENOUGH MIXING WILL CONTINUE TO KEEP TEMPERATURES SEVERAL DEGREES HIGHER THAN PAST SEVERAL NIGHTS. HAVE RAISED HRLY TEMPS AND OVERNIGHT MINS A FEW DEGREES...MOST AREAS LOOK TO BOTTOM OUT IN THE UPR 60S TO LWR 70S. INCREASING MID/HIGH LVL CLOUDS ARE MOVING INTO WRN VA AND NC...AND THESE CLOUDS SHOULD OVERSPREAD THE CWA AFTER 06Z...AND SLOWLY THICKEN UP A BIT. OVERALL EXPECT CLR CONDITIONS GIVING WAY TO PTLY CLDY SKIES WELL AFTER MIDNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... WEDNESDAY AND WEDNESDAY NIGHT...AFOREMENTIONED COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA ON WEDNESDAY INTO WEDNESDAY EVENING. HOWEVER.. LACK OF OVERALL MOISTURE AND WESTERLY DOWN SLOPE FLOW SHOULD HELP KEEP THE FRONT DRY. CANNOT RULE OUT AN ISOLATED SHOWER AND/OR SPRINKLES ALONG THE FRONT... BUT WILL LEAVE OUT MENTION OF PRECIP FOR NOW GIVEN THE UNFAVORABLE SETUP AND ONLY SHOW AN INCREASE IN CLOUD COVER WITH THE FRONT (PARTLY CLOUDY SKIES). LOW LEVEL THICKNESS VALUES AREA EXPECTED TO INCREASE INTO THE 1420S FOR WEDNESDAY AFTERNOON. THIS COUPLE WITH THE DOWN SLOPE FLOW SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S... WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION... IT WILL BE A BIT BREEZY ON WEDNESDAY AFTERNOON... WITH SOUNDINGS SHOWING AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR WEDNESDAY NIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD... WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS... WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUIET WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMIT POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... SURFACE OBS SHOWING CLEAR SKIES AND LIGHT S WINDS. WINDS WILL REMAIN A BIT HIGHER TONIGHT AND WILL PREVENT ANY FOG FORMATION AT THE TAF SITES. HIGH CLOUDS WILL BEGIN TO COME IN WED MORNING AHEAD OF THE COLD FRONT AND WILL THICKEN AND LOWER THROUGHOUT THE DAY. VFR CONDITIONS ARE STILL EXPECTED ALL DAY WED. EXPECT WINDS TO PICK UP AND SHIFT TO THE W DURING THE DAY. VFR CONDITIONS WILL PREVAIL AS HIGH PRESSURE BUILDS BACK INTO THE AREA THROUGH SAT. && .MARINE... CURRENT OBSERVATIONS INDICATE THE WIND IS INCREASING OVER THE LOWER BAY AND NEARING SMALL CRAFT CRITERIA. ADDITIONALLY...THE LATEST HIGH RESOLUTION MODEL GUIDANCE SUGGESTS A PERIOD OF MARGINAL SMALL CRAFT CONDITIONS THROUGH THE EVENING AND OVERNIGHT HOURS. HENCE A SMALL CRAFT FLAG WAS RAISED FOR THE LOWER BAY COINCIDENT WITH THE INHERITED FLAG TO THE NORTH. OTHERWISE...THERE WERE NO CHANGES TO THE LATEST MARINE FORECAST. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA INTO A DEVELOPING LEE TROUGH...EXPECT A WIND SHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY DELTA TEMPS AROUND 12C WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. EXPECT JUST A BRIEF PERIOD OF THESE CONDITIONS OVERNIGHT. -BLAES && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ630>632. && $$ SYNOPSIS...LKB NEAR TERM...LKB SHORT TERM...BSD LONG TERM...BSD AVIATION...DAP MARINE...AJZ/BLAES 000 FXUS61 KLWX 080126 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 926 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE COAST THROUGH TONIGHT. A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO WEDNESDAY... BRINGING BREEZY CONDITIONS. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND PERSIST INTO THE WEEKEND. ANOTHER COLD FRONT WILL IMPACT THE REGION SUNDAY...WHICH WILL BE FOLLOWED BY MORE HIGH PRESSURE. && .NEAR TERM /THROUGH WEDNESDAY/... HIPRES WILL CONTINUE TO PUSH OFF THE MID-ATLANTIC COAST TNGT AS A COLD FRONT OVER THE MIDWEST PUSHES THRU THE OH VLY THIS EVE AND ACROSS THE CENTRAL APPALACHIANS LATE TONIGHT. THE FRONT SHOULD BEGIN TO ENTER THE WRN SLOPES OF THE ALLEGHENY FRONT AROUND DAYBREAK WED MRNG. THE RECENT LOCAL MODELS AND 18Z NAM AND GFS PAINT AN INCONSISTENT PICTURE WHETHER THE THUNDERSTORMS OVER EASTERN OH AND WESTERN PA WILL MAKE IT INTO OUR CWA. THE HRRR/WRF GFS NAM AND RUC SAY NO...WHILE A FEW OF THE LATEST LOCAL WRFS SAY THEY MAY. DOWNSLOPING IN THE MIDLEVELS AND DECREASING INSTAB AHEAD OF THE FRONT WITH THE DIURNAL MIN SHOULD HELP TO KEEP THEM FROM MOVING THRU. FOR NOW WILL MAINTAIN THE CHANCES IN OUR MOUNTAIN WEST AND WILL SEE HOW THE NEXT FEW HOURS GO. OTHER THREAT WED MORNING WILL BE MINOR TIDAL FLOODING. AM EXPECTING AT LEAST AN EQUAL TIDAL LEVEL FOR HIGH TIDE WED MORNING IF NOT SLIGHTLY HIGHER WITH A CONTINUED S PUSH OF WATER UP THE BAY WITH NEW MOON. WILL CONSIDER ANOTHER COASTAL FLOOD ADVISORY FOR WED MORNING FOR AT LEAST PART OF THE TIDAL AREA IN OUR FORECAST AREA. THE FRONT WILL CROSS THE I-95 CORRIDOR IN THE MRNG...AND PUSH THRU LOWER SRN MD BY THE ERY AFTN. AFTER AN INCREASE IN MID TO UPPER CLOUDS ASSOCIATED WITH THE FROPA IN THE MRNG...SKIES WILL CLEAR OUT BEHIND THE FRONT AS THE ENTIRE COLUMN QUICKLY DRIES OUT. GUSTY WESTERLY WINDS ARE EXPECTED TO INCREASE TO 15-20 MPH WITH GUSTS TO 30 MPH POSSIBLE DURING THE AFTN. SEE FIRE SECTION FOR DISCUSSION OF FIRE THREAT ON WED. DAYTIME HIGHS WED WILL RANGE FROM THE 70S ACROSS THE RIDGE TOPS TO MU80S EAST OF THE BLUE RIDGE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT IN THE WAKE OF THE DAYTIME FROPA WITH DOWNSLOPING WLY FLOW ENSURING DRY AND CLEAR CONDITIONS /ANY SKY COVER WOULD BE HIGH CLOUDS/. COLD AIR ADVECTION TO PREVENT DECOUPLING...MIN TEMPS AROUND 60F EAST OF I-95...LOW TO MID 50S INLAND...LOW 40S FOR HIGH ELEVATIONS OUT WEST. THURSDAY THROUGH FRIDAY NIGHT...UPPER LOW DRIFTS EAST ACROSS NEW ENGLAND AS A RIDGE AMPLIFIES AS IT BUILDS EAST ACROSS THE MIDWEST. THIS WILL MAINTAIN DRY NWLY FLOW WITH SUNNY/CLEAR CONDITIONS MAX TEMPS LIMITED TO UPPER 70S /JUST BELOW NORMAL/. MIN TEMPS A FEW DEGREES BELOW NORMAL BOTH NIGHTS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A COLD FRONT ASSOCIATED WITH A LOW OVER NRN ONTARIO LOOKS TO IMPACT THE MID ATLANTIC IN THE SUNDAY TIMEFRAME. WENT WITH A BLEND OF THE QUICKER GFS AND SLOWER ECMWF FOR A SUNDAY AFTERNOON/EVENING FROPA ATTM. REMNANT MOISTURE FROM HERMINE SHOULD BE PICKED UP FROM THIS SYSTEM...SO HOPEFULLY THIS WILL BE A MORE WIDESPREAD RAIN EVENT...THOUGH A WEST TO EAST FROPA WOULD SUGGEST SCATTERING PRECIP AS IT PASSES THE APPALACHIANS. MORE HIGH PRESSURE POST FROPA. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS TNGT AND WED. S-SW WINDS WILL CONTINUE TO DIMINISH TONIGHT. MTN AND DCA WILL LIKELY HOLD ON THE LONGEST BEING CLOSE TO THE WATER. A COLD FRONT WILL MOVE THRU THE TERMINALS WED MRNG. FROPA WILL BE MARKED BY A WINDSHIFT FROM THE WEST. DURING THE LATE MRNG INTO THE AFTN...SUSTAINED WINDS WILL INCREASE TO AROUND 15 KT...WITH GUSTS 20-25 KT POSSIBLE. POST FROPA WLY/NWLY FLOW WITH VFR CONDS WED NIGHT INTO THE WEEKEND. NEXT COLD FRONT IN THE SUNDAY TIMEFRAME. && .MARINE... WINDS ARE SLACKENING OUTSIDE OF THE MAIN CHANNEL OF THE BAY S OF POOLES AND THE LOWERMOST PART OF THE POTOMAC. WILL ALLOW SCA TO EXPIRE AT 02Z FOR THE SLACKENING AREAS WHILE CONTINUING WITH THE EXISTING SCA FOR THE BAY AND LOWR POTOMAC THRU TNT. A COLD FRONT WILL MOVE THRU THE WATERS LATE WED MRNG INTO THE ERY AFTN. WIDESPREAD GUSTS OF 20 KT EXPECTED BEHIND THE FRONT. EXTENDED SCA THROUGH WEDNESDAY NIGHT FOR THE MD BAY/SRN TIDAL POTOMAC AND EASTERN TRIBUTARIES /NOT PATAPSCO OR PAX RIVER/ WITH POST FROPA WLY/NWLY COOL FLOW MIXING DOWN OVER THE WARM WATER. NEAR SCA NWLY FLOW THEN PERSISTS INTO THE WEEKEND WITH AND UPPER LOW OVER NEW ENGLAND...SCA/S MORE LIKELY IF WIND IS ABLE TO VEER TO NLY AND CHANNEL DOWN THE BAY. && .FIRE WEATHER... EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE...GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. PLEASE NOTE- BURNING BAN FOR ERN WV PANHANDLE WENT INTO EFFECT THIS MRNG AND WILL CONTINUE UNTIL FURTHER NOTICE. A COLD FRONT WILL MOVE THRU THE REGION LATE TNGT INTO WED. BREEZY AND DRY CONDITIONS ARE EXPECTED BEHIND THE FRONT ON WED. RED FLAG CONDITIONS ARE POSSIBLE ON WED WITH SUSTAINED WINDS APPROACHING 20 MPH AND MIN AFTN RH VALUES BETWEEN 25-30 PERCENT COMBINED WITH THE ALREADY LOW FUEL MOISTURE. AFTER TALKING TO STATE FIRE OFFICIALS...A A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MOST OF THE CWFA...WITH THE EXCLUSION OF THE NRN PIEDMONT AND CENTRAL FOOTHILLS IN VA /WHERE WINDS WILL LIGHTER/. WILL COORDINATE WITH STATE FIRE OFFICIALS IN THE MRNG WHEN WRNG HEADLINE DECISIONS ARE MADE. NWLY FLOW WILL CONTINUE FOR THURSDAY AND FRIDAY...MAINTAINING AN ENHANCED FIRE WX THREAT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR DCZ001. MD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR MDZ003>007-009>011-013-014-016>018-501-502. VA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR VAZ021-025>031-038>040-042-051>054-501-502. WV...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR WVZ050>055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ531>534- 537-539>541-543. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ530- 535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM TO 8 PM EDT WEDNESDAY FOR ANZ535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO 6 AM EDT THURSDAY FOR ANZ530. && $$ SYNOPSIS...BAJ NEAR TERM...CS/JRK SHORT TERM...BAJ LONG TERM...BAJ AVIATION...CS/BAJ/JRK MARINE...CS/BAJ/JRK FIRE WEATHER...JRK/BAJ 000 FXUS61 KPBZ 080111 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 911 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING SCATTERED THUNDERSTORMS. THIS FRONT WILL BRING MUCH COOLER TEMPERATURES INTO LATE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 9PM...COLD FRONT CONTINUES TO MOVE ACROSS THE REGION. THUNDERSTORM COVERAGE HAS BEEN SCATTERED ALONG THE FRONT...WITH ISOLATED SEVERE THUNDERSTORM REPORTS. THERE REMAINS A SMALL CHANCE THAT THERE COULD BE ADDITIONAL SEVERE WEATHER...BUT THE LOSS OF DAYTIME HEATING SHOULD DIMINISH THE STRENGTH OF THUNDERSTORMS. BEHIND THE FRONT MUCH COOLER AIR WILL ARRIVE BY MORNING WITH LOWS IN THE MID TO UPPER 50S. WITH NORTHWEST WINDS WEDNESDAY EXPECT SOME CLOUDS ACROSS THE NORTHERN TIER OFF THE LAKES AND POSSIBLY A SPRINKLE. TEMPERATURES WILL BE MUCH COOLER WITH UPPER 60S NORTH UNDER CLOUDS TO MID 70S SOUTH WHERE SUNSHINE PREVAILS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL LOW WILL SPIN ACROSS THE NORTHERN LAKES TO NEW ENGLAND THROUGH THE PERIOD WITH NORTHWEST FLOW TO DOMINATE WEATHER. EXPECT CLOUDS OFF OF THE LAKES TO BE ACROSS THE NORTH IN A DIURNAL FASHION WITH A SPRINKLE OR TWO POSSIBLE FAR NORTH. OTHERWISE SEASONABLY COOL THROUGH THE PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY THROUGH END OF FORECAST PERIOD. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... COLD FRONT WILL MOVE THROUGH THIS EVENING WITH SCATTERED -SHRA AND -TSRA...GUSTS POSSIBLE TO 30 KTS. FRONT MOVES OUT OF REGION BY EARLY WEDNESDAY MORNING. STRONG NW FLOW DEVELOPING BY 15Z-18Z WEDNESDAY (NW 28015G28KT). STRATO-CU DECK BKN ACROSS NORTHERN HALF/TWO THIRDS OF FORECAST AREA ON WEDNESDAY. HIGH PRESSURE BUILDS IN FOR THURSDAY WITH VFR. FRIDAY...HIGH PRESSURE STILL IN CONTROL WITH VFR CONTINUING. NEXT FRONTAL SYSTEM APPROACHES SATURDAY WITH LINGERING SHOWERS POSSIBLE INTO EARLY SUNDAY. MVFR IN SHOWERS OR ANY STORMS SATURDAY INTO SUNDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPBZ 080015 AAA AFDPBZ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 815 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING A CHANCE OF SHOWERS. THIS FRONT WILL BRING MUCH COOLER TEMPERATURES INTO LATE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... COLD FRONT ACROSS NORTHWEST OHIO WILL WORK ACROSS REGION THIS EVENING WITH A SCATTERED BAND OF SHOWERS AND A FEW THUNDERSTORMS EXPECTED. BEHIND THE FRONT MUCH COOLER AIR WILL ARRIVE BY MORNING WITH LOWS IN THE MID TO UPPER 50S. WITH NORTHWEST WINDS WEDNESDAY EXPECT SOME CLOUDS ACROSS THE NORTHERN TIER OFF THE LAKES AND POSSIBLY A SPRINKLE. TEMPERATURES WILL BE MUCH COOLER WITH UPPER 60S NORTH UNDER CLOUDS TO MID 70S SOUTH WHERE SUNSHINE PREVAILS. SPS ISSUED FOR ELEVATED FIRE DANGER INTO THIS EVENING BEFORE RELATIVE HUMIDITY RISES AS FRONT APPROACHES. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL LOW WILL SPIN ACROSS THE NORTHERN LAKES TO NEW ENGLAND THROUGH THE PERIOD WITH NORTHWEST FLOW TO DOMINATE WEATHER. EXPECT CLOUDS OFF OF THE LAKES TO BE ACROSS THE NORTH IN A DIURNAL FASHION WITH A SPRINKLE OR TWO POSSIBLE FAR NORTH. OTHERWISE SEASONABLY COOL THROUGH THE PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. CLOSE TO HPC PROGS THROUGH PERIOD. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY BEYOND THOUGH END OF FORECAST PERIOD. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... COLD FRONT WILL MOVE THROUGH THIS EVENING WITH SCATTERED -SHRA AND -TSRA...GUSTS POSSIBLE TO 30 KTS. FRONT MOVES OUT OF REGION BY EARLY WEDNESDAY MORNING. STRONG NW FLOW DEVELOPING BY 15Z-18Z WEDNESDAY (NW 28015G28KT). STRATO-CU DECK BKN ACROSS NORTHERN HALF/TWO THIRDS OF FORECAST AREA ON WEDNESDAY. HIGH PRESSURE BUILDS IN FOR THURSDAY WITH VFR. FRIDAY...HIGH PRESSURE STILL IN CONTROL WITH VFR CONTINUING. NEXT FRONTAL SYSTEM APPROACHES SATURDAY WITH LINGERING SHOWERS POSSIBLE INTO EARLY SUNDAY. MVFR IN SHOWERS OR ANY STORMS SATURDAY INTO SUNDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 072354 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 754 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT...AND CROSS THE AREA WEDNESDAY MORNING. AHEAD OF THE FRONT...THERE MAY BE A FEW SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS NORTH AREAS LATE TONIGHT AND WEDNESDAY MORNING. BEHIND THE FRONT...COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILD INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL CROSS THE AREA SUNDAY...FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE APPROACHING COLD FRONT OVER THE OHIO VALLEY AND GREAT LAKES HAS CREATED CONVECTION ACROSS ERN OHIO...NW PENNSYLVANIA AND WRN NY. CLOUDS FROM THIS CONVECTION WILL SPREAD ACROSS OUR AREA OVER THE NEXT FEW HOURS. SKY GRIDS WERE ADJUSTED ACCORDINGLY WITH MORE CLOUDS INSERTED INTO THE OVERNIGHT FORECAST. TEMPS/DEW POINTS ANDS WINDS ARE ADJUSTED SLIGHTLY ALSO. THIS ACTIVITY WILL TRY TO CROSS PENNSYLVANIA AND NEW YORK STATE DURING THE OVERNIGHT HOURS. THE AIRMASS WILL STABILIZE LATER THIS EVENING AND THIS MAY HELP ERODE THE CONVECTION THAT MOVES EAST. THERE IS SOME INDICATION OF SOME ELEVATED INSTABILITY LATE TONIGHT ACROSS WESTERN ZONES...AND THIS COULD HELP THE CONVECTION THAT MOVES EAST TO REMAIN INTACT. BASED ON THE BEST MOISTURE AND PROJECTED INSTABILITY...LIMITED THE MENTION OF SHOWERS AND THUNDERSTORMS TO NORTH OF A KRDG-KSMQ-KMMU LINE...GENERALLY BETWEEN 0800 UTC AND 1200 UTC WEDNESDAY. THE MID LEVEL WIND MAX WEAKENS AS IT MOVES EAST. WHILE THERE MAY BE SOME GUSTINESS WITH ANY THUNDERSTORMS THAT DEVELOP...WILL NOT MENTION IT AT THIS TIME DUE TO UNCERTAINTY. FOR THE MOST PART...WITH THE SOUTHWEST FLOW AHEAD OF THE FRONT AND HIGHER DEW POINTS IN PLACE...WENT ABOVE ALL MOS NUMBERS FOR LOWS TONIGHT. IT APPEARS AS THOUGH THE FRONT ARRIVES LATE ENOUGH TONIGHT NOT TO HAVE AN INFLUENCE ON LOW TEMPERATURES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A VFR FORECAST WAS ISSUED WITH THE 00Z TAFS. LINE OF CONVECTIVE SHRAS AND TSTMS IS FORECAST TO WEAKEN/DISPERSE AS IT APPROACHES OUR CWA OVERNIGHT. NOT CONFIDENT THAT THEY MAKE IT TO ANY SPECIFIC TERMINAL AND IF THEY DO ANY PCPN REDUCTIONS TO VSBYS AND CIGS MAY VERY WELL STAY IN THE VFR CATEGORY. IF WE ARE WRONG MOST LIKELY PLACES IT WOULD BE KABE AND KRDG AND THEIR ARRIVAL WOULD NOT BE UNTIL AFTER 06Z. OTHERWISE FOR THE OVERNIGHT WE ARE FORECASTING RESIDUAL MID AND HIGH LEVEL CLOUDS TO OVERSPREAD THE TERMINALS. THE LATEST 18Z GUIDANCE WEAKENED THE LLJ A BIT AND WE REDUCED THE TIME OF LLWS POTENTIAL FROM THE KPHL METRO AREA AIRPORTS SEWD. THE LLJ WINDS ARE FORECAST TO REMAIN THE STRONGEST, THE LONGEST AT KABE AND KRDG. THE COLD FRONT SHOULD MOVE THRU THE TERMINALS FROM NW TO SE APPROXIMATELY 11Z TIL 14Z AND WINDS SHOULD INCREASE FROM THE WEST FAIRLY RAPIDLY POST COLD FRONTAL. NOT MUCH MOISTURE WILL BE LEFT IN ITS WAKE AND ONLY A FEW VERY HIGH BASED CUMULUS CLOUDS ARE FORECAST. IT WILL BE WINDY AND PEAK WIND GUSTS SHOULD AVERAGE AROUND 30KTS ESPECIALLY AT THE WINDIER TERMINALS LIKE KPHL. WINDS SHOULD DECREASE RAPIDLY WED EVE. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... WE ARE GOING TO EXTEND THE SCA TO ALL OF THE COASTAL WATERS EXCEPT FOR UPPER DELAWARE BAY. WINDS AND SEAS CONTINUE TO INCREASE AND WITH STRONGER WINDS FORECAST ALOFT OVERNIGHT AND LESS OF AN AIR/WATER DIFFERENTIAL DO NOT SEE THIS TREND REVERSING. WILL LEAVE UPPER DELAWARE BAY OUT FOR NOW AS THERE IS SOME DECOUPLING OCCURRING OVER THE LAND AND THE WIDTH OF THAT PART OF THE BAY MAY NOT BE WIDE ENOUGH TO BRING ENOUGH MIXED WIND BAYWARD. ONCE THE FRONT CROSSES OUR AREA WEDNESDAY, WINDS WILL SHIFT TO THE WEST. THE WIND SHIFT WILL KNOCK DOWN THE SEAS ALSO. THE HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE AREA, BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... WILL CONVERT THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED, POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ431- 450>455. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES/O`HARA SHORT TERM...HAYES LONG TERM...GIGI AVIATION...GIGI/RPW MARINE...GIGI/RPW FIRE WEATHER... CLIMATE... 000 FXUS61 KPHI 072341 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 741 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT...AND CROSS THE AREA WEDNESDAY MORNING. AHEAD OF THE FRONT...THERE MAY BE A FEW SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS NORTH AREAS LATE TONIGHT AND WEDNESDAY MORNING. BEHIND THE FRONT...COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILD INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL CROSS THE AREA SUNDAY...FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE RETURN FLOW AROUND THE HIGH CENTERED OFFSHORE BROUGHT WARMER AND MORE HUMID CONDITIONS FOR THIS AFTERNOON WITH MARGINAL INSTABILITY. WITHOUT A FOCUS...THIS INSTABILITY SHOULD REMAIN UNTAPPED INTO THE EVENING HOURS. THE FEW CUMULUS THAT DEVELOPED WILL DISSIPATE DURING THE EVENING HOURS...AS HIGH CLOUDS CROSS THE AREA. THE SURFACE COLD FRONT LYING ACROSS THE GREAT LAKES AND WESTERN OHIO VALLEY HAS HAD COME BRIEF CONVECTION WITH IT THIS AFTERNOON...BUT THE AIRMASS AHEAD OF THE FRONT IS STILL FAIRLY STABLE. WOULD EXPECT THE CONVECTION TO BECOME A BIT BETTER ORGANIZED AS IT APPROACHES WESTERN NEW YORK STATE AND WESTERN PENNSYLVANIA THIS EVENING...AS THE IN SITU INSTABILITY IS ENHANCED BY A DECENT MID LEVEL WIND MAXIMUM. THIS ACTIVITY WILL TRY TO CROSS PENNSYLVANIA AND NEW YORK STATE DURING THE OVERNIGHT HOURS. THE AIRMASS WILL STABILIZE THIS EVENING AND THIS MAY HELP ERODE THE CONVECTION THAT MOVES EAST. THERE IS SOME INDICATION OF SOME ELEVATED INSTABILITY LATE TONIGHT ACROSS WESTERN ZONES...AND THIS COULD HELP THE CONVECTION THAT MOVES EAST TO REMAIN INTACT. BASED ON THE BEST MOISTURE AND PROJECTED INSTABILITY...LIMITED THE MENTION OF SHOWERS AND THUNDERSTORMS TO NORTH OF A KRDG-KSMQ-KMMU LINE...GENERALLY BETWEEN 0800 UTC AND 1200 UTC WEDNESDAY. THE MID LEVEL WIND MAX WEAKENS AS IT MOVES EAST. WHILE THERE MAY BE SOME GUSTINESS WITH ANY THUNDERSTORMS THAT DEVELOP...WILL NOT MENTION IT AT THIS TIME DUE TO UNCERTAINTY. FOR THE MOST PART...WITH THE SOUTHWEST FLOW AHEAD OF THE FRONT AND HIGHER DEW POINTS IN PLACE...WENT ABOVE ALL MOS NUMBERS FOR LOWS TONIGHT. IT APPEARS AS THOUGH THE FRONT ARRIVES LATE ENOUGH TONIGHT NOT TO HAVE AN INFLUENCE ON LOW TEMPERATURES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A VFR FORECAST WAS ISSUED WITH THE 00Z TAFS. LINE OF CONVECTIVE SHRAS AND TSTMS IS FORECAST TO WEAKEN/DISPERSE AS IT APPROACHES OUR CWA OVERNIGHT. NOT CONFIDENT THAT THEY MAKE IT TO ANY SPECIFIC TERMINAL AND IF THEY DO ANY PCPN REDUCTIONS TO VSBYS AND CIGS MAY VERY WELL STAY IN THE VFR CATEGORY. IF WE ARE WRONG MOST LIKELY PLACES IT WOULD BE KABE AND KRDG AND THEIR ARRIVAL WOULD NOT BE UNTIL AFTER 06Z. OTHERWISE FOR THE OVERNIGHT WE ARE FORECASTING RESIDUAL MID AND HIGH LEVEL CLOUDS TO OVERSPREAD THE TERMINALS. THE LATEST 18Z GUIDANCE WEAKENED THE LLJ A BIT AND WE REDUCED THE TIME OF LLWS POTENTIAL FROM THE KPHL METRO AREA AIRPORTS SEWD. THE LLJ WINDS ARE FORECAST TO REMAIN THE STRONGEST, THE LONGEST AT KABE AND KRDG. THE COLD FRONT SHOULD MOVE THRU THE TERMINALS FROM NW TO SE APPROXIMATELY 11Z TIL 14Z AND WINDS SHOULD INCREASE FROM THE WEST FAIRLY RAPIDLY POST COLD FRONTAL. NOT MUCH MOISTURE WILL BE LEFT IN ITS WAKE AND ONLY A FEW VERY HIGH BASED CUMULUS CLOUDS ARE FORECAST. IT WILL BE WINDY AND PEAK WIND GUSTS SHOULD AVERAGE AROUND 30KTS ESPECIALLY AT THE WINDIER TERMINALS LIKE KPHL. WINDS SHOULD DECREASE RAPIDLY WED EVE. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... WE ARE GOING TO EXTEND THE SCA TO ALL OF THE COASTAL WATERS EXCEPT FOR UPPER DELAWARE BAY. WINDS AND SEAS CONTINUE TO INCREASE AND WITH STRONGER WINDS FORECAST ALOFT OVERNIGHT AND LESS OF AN AIR/WATER DIFFERENTIAL DO NOT SEE THIS TREND REVERSING. WILL LEAVE UPPER DELAWARE BAY OUT FOR NOW AS THERE IS SOME DECOUPLING OCCURRING OVER THE LAND AND THE WIDTH OF THAT PART OF THE BAY MAY NOT BE WIDE ENOUGH TO BRING ENOUGH MIXED WIND BAYWARD. ONCE THE FRONT CROSSES OUR AREA WEDNESDAY, WINDS WILL SHIFT TO THE WEST. THE WIND SHIFT WILL KNOCK DOWN THE SEAS ALSO. THE HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE AREA, BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... WILL CONVERT THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED, POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ431-450>455. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES LONG TERM...GIGI AVIATION...GIGI/RPW MARINE...GIGI/RPW FIRE WEATHER...HAYES CLIMATE...DRAG 000 FXUS61 KAKQ 072239 AAA AFDAKQ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WAKEFIELD VA 639 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH WEDNESDAY. A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION WEDNESDAY NIGHT. AS HIGH PRESSURE BUILDS SOUTH ACROSS THE AREA THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 320 PM TUESDAY... 18Z SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED JUST NE OF THE NC OUTER BANKS. RIDGE AXIS EXTENDS FROM SW TO NE ACROSS CENTRAL AND NE NORTH CAROLINA AND THEN OFFSHORE. A LEE TROUGH WAS ANALYZED JUST EAST OF THE BLUE RIDGE FROM W MD SOUTHWARD TO W NC. LATEST VIS SAT IMAGERY SHOWS A LARGE AREA OF FEW-SCT CUMULUS WITH BASES AROUND 5KFT. SOUTH-SOUTHEASTERLY SFC WINDS HAVE PICKED UP A BIT NORTH OF THE RIDGE AS THE SFC GRADIENT HAS TIGHTENED WITH THE APPROACHING COLD FRONT. SW WINDS AROUND 10 KTS WITH GUSTS OF 15-20 KTS THIS AFTN WILL LIGHTEN UP CONSIDERABLY AFTER SUNSET. STILL EXPECT WINDS TO REMAIN UP OVERNIGHT WHICH SHOULD PRECLUDE ANY GROUND FOG DESPITE INCREASING LOW LEVEL MOISTURE. DIURNALLY FORCED CU SHOULD WANE AROUND SUNSET WITH SOME INCREASE IN HIGH CLOUDS EXPECTED OVERNIGHT...MAINLY NORTHWEST OF KRIC. MOS GUIDANCE IN GOOD AGREEMENT AND EXPECT LOW TEMPS TO GENERALLY RANGE IN THE UPPER 60S TO LOWER 70S. -BLAES && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... AS OF 215 PM TUESDAY... WEDNESDAY AND WEDNESDAY NIGHT...AFOREMENTIONED COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA ON WEDNESDAY INTO WEDNESDAY EVENING. HOWEVER.. LACK OF OVERALL MOISTURE AND WESTERLY DOWN SLOPE FLOW SHOULD HELP KEEP THE FRONT DRY. CANNOT RULE OUT AN ISOLATED SHOWER AND/OR SPRINKLES ALONG THE FRONT... BUT WILL LEAVE OUT MENTION OF PRECIP FOR NOW GIVEN THE UNFAVORABLE SETUP AND ONLY SHOW AN INCREASE IN CLOUD COVER WITH THE FRONT (PARTLY CLOUDY SKIES). LOW LEVEL THICKNESS VALUES AREA EXPECTED TO INCREASE INTO THE 1420S FOR WEDNESDAY AFTERNOON. THIS COUPLE WITH THE DOWN SLOPE FLOW SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S... WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION... IT WILL BE A BIT BREEZY ON WEDNESDAY AFTERNOON... WITH SOUNDINGS SHOWING AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR WEDNESDAY NIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD... WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS... WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 215 PM TUESDAY... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUITE WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMITED POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 130 PM TUESDAY... VFR CONDITIONS EXPECTED THROUGH WED AFTN. LATEST SFC ANALYSIS SHOWS HIGH PRESSURE CENTER LOCATED JUST NO OF THE NC OUTER BANKS. RIDGE AXIS EXTENDS FROM SW TO NE ACROSS CENTRAL AND NE NORTH CAROLINA AND THEN OFFSHORE. LATEST VIS SAT IMAGERY SHOWS A LARGE AREA OF FEW-SCT CU WITH BASES AROUND 5KFT...ESPECIALLY FROM THE RICHMOND AND HAMPTON ROADS AREA SOUTHWEST. SOUTH-SOUTHEASTERLY SFC WINDS HAVE PICKED UP A BIT NORTH OF THE RIDGE AS THE SFC GRADIENT HAS TIGHTENED WITH THE APPROACHING COLD FRONT. DIURNALLY FORCED CU SHOULD WANE AROUND SUNSET WITH SOME INCREASE IN HIGH CLOUDS EXPECTED OVERNIGHT...MAINLY AT KRIC AND KSBY. EXPECT WINDS TO REMAIN UP OVERNIGHT WHICH SHOULD PRECLUDE ANY GROUND FOG DESPITE INCREASING LOW LEVEL MOISTURE...ONLY EXCEPTION MIGHT BE KECG WHICH WILL BE MORE MOIST AND CLOSER TO THE SFC RIDGE. COLD FRONT DROPS SOUTH AND APPROACHES THE NORTHERN TAF SITES AFTER 18Z. LEE TROFINESS AHEAD OF THE FRONT WILL PROMOTE A MORE WESTWARD SFC WIND AND A BIT STRONGER AND MORE GUSTY. MID AND HIGH LEVEL MOISTURE WILL INCREASE DURING THE DAY SO SHOULD SEE ANOTHER ROUND OF DIURNAL CU ALONG WITH SCT-BKN ALTO/CIRRUS LEVEL CLOUDINESS. EXPECT THE FRONT TO BE MAINLY DRY SO DO NOT EXPECT AND VSBY RESTRICTIONS WITH ANY CIGS ABOVE 5KFT. LOOKING FURTHER AHEAD...GENERALLY VFR CONDITIONS ARE EXPECTED FROM LATE WED INTO FRIDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH AND WEST. A WARM FRONT WILL APPROACH THE REGION FROM THE SOUTHWEST DURING THE WEEKEND WHICH COULD BRING A CHANCE OF SCT MAINLY AFTN/EVEN SHOWERS OR THUNDERSTORMS. -BLAES && .MARINE... CURRENT OBSERVATIONS INDICATE THE WIND IS INCREASING OVER THE LOWER BAY AND NEARING SMALL CRAFT CRITERIA. ADDITIONALLY...THE LATEST HIGH RESOLUTION MODEL GUIDANCE SUGGESTS A PERIOD OF MARGINAL SMALL CRAFT CONDITIONS THROUGH THE EVENING AND OVERNIGHT HOURS. HENCE A SMALL CRAFT FLAG WAS RAISED FOR THE LOWER BAY COINCIDENT WITH THE INHERITED FLAG TO THE NORTH. OTHERWISE...THERE WERE NO CHANGES TO THE LATEST MARINE FORECAST. PREVIOUS DISCUSSION... LATEST ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED JUST NE OF THE NORTHERN OUTER BANKS. A RIDGE AXIS EXTENDS SW FROM THE HIGH CENTER ACROSS NORTHEAST NC. LATEST MARINE OBS INDICATE MAINLY S TO SSW WINDS AT 10-14KTS ACROSS THE NORTHERN AND CENTRAL CHES BAY WITH GUSTS OF AROUND 15 KTS...OCCASIONALLY APPROACHING 20 KTS. WINDS ARE LIGHTER FURTHER SOUTH IN CLOSER PROXIMITY TO THE SFC RIDGE. PATTERN TONIGHT OF WARM ADVECTION ON THE WESTERN SIDE OF A SHIFTING HIGH CENTER SUGGESTS WINDS TO REMAIN UP TONIGHT. NAM/SREF GUIDANCE STILL SHOWS 15-20KTS OF S/SW FLOW AHEAD OF THE FRONT TONIGHT. WILL MAINTAIN MINIMAL SCA CRITERIA OVER THE CEN/NRN PTNS OF CHES BAY. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA INTO A DEVELOPING LEE TROUGH...EXPECT A WIND SHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY DELTA TEMPS AROUND 12C WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. EXPECT JUST A BRIEF PERIOD OF THESE CONDITIONS OVERNIGHT. -BLAES && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ630>632. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BSD LONG TERM...BSD AVIATION...BLAES MARINE...BLAES/AJZ 000 FXUS61 KPHI 072224 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 624 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT...AND CROSS THE AREA WEDNESDAY MORNING. AHEAD OF THE FRONT...THERE MAY BE A FEW SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS NORTH AREAS LATE TONIGHT AND WEDNESDAY MORNING. BEHIND THE FRONT...COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILD INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL CROSS THE AREA SUNDAY...FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE RETURN FLOW AROUND THE HIGH CENTERED OFFSHORE BROUGHT WARMER AND MORE HUMID CONDITIONS FOR THIS AFTERNOON WITH MARGINAL INSTABILITY. WITHOUT A FOCUS...THIS INSTABILITY SHOULD REMAIN UNTAPPED INTO THE EVENING HOURS. THE FEW CUMULUS THAT DEVELOPED WILL DISSIPATE DURING THE EVENING HOURS...AS HIGH CLOUDS CROSS THE AREA. THE SURFACE COLD FRONT LYING ACROSS THE GREAT LAKES AND WESTERN OHIO VALLEY HAS HAD COME BRIEF CONVECTION WITH IT THIS AFTERNOON...BUT THE AIRMASS AHEAD OF THE FRONT IS STILL FAIRLY STABLE. WOULD EXPECT THE CONVECTION TO BECOME A BIT BETTER ORGANIZED AS IT APPROACHES WESTERN NEW YORK STATE AND WESTERN PENNSYLVANIA THIS EVENING...AS THE IN SITU INSTABILITY IS ENHANCED BY A DECENT MID LEVEL WIND MAXIMUM. THIS ACTIVITY WILL TRY TO CROSS PENNSYLVANIA AND NEW YORK STATE DURING THE OVERNIGHT HOURS. THE AIRMASS WILL STABILIZE THIS EVENING AND THIS MAY HELP ERODE THE CONVECTION THAT MOVES EAST. THERE IS SOME INDICATION OF SOME ELEVATED INSTABILITY LATE TONIGHT ACROSS WESTERN ZONES...AND THIS COULD HELP THE CONVECTION THAT MOVES EAST TO REMAIN INTACT. BASED ON THE BEST MOISTURE AND PROJECTED INSTABILITY...LIMITED THE MENTION OF SHOWERS AND THUNDERSTORMS TO NORTH OF A KRDG-KSMQ-KMMU LINE...GENERALLY BETWEEN 0800 UTC AND 1200 UTC WEDNESDAY. THE MID LEVEL WIND MAX WEAKENS AS IT MOVES EAST. WHILE THERE MAY BE SOME GUSTINESS WITH ANY THUNDERSTORMS THAT DEVELOP...WILL NOT MENTION IT AT THIS TIME DUE TO UNCERTAINTY. FOR THE MOST PART...WITH THE SOUTHWEST FLOW AHEAD OF THE FRONT AND HIGHER DEW POINTS IN PLACE...WENT ABOVE ALL MOS NUMBERS FOR LOWS TONIGHT. IT APPEARS AS THOUGH THE FRONT ARRIVES LATE ENOUGH TONIGHT NOT TO HAVE AN INFLUENCE ON LOW TEMPERATURES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. EXCELLENT FLYING WX CONTINUES THIS AFTERNOON AS AN AREA OF HIGH PRESSURE MOVES SLOWLY OFF TO THE SOUTH AND EAST. NOTHING MORE THAN AN FEW FAIR WEATHER CU AND SOME HIGH THIN CI ONCE AGAIN. LIGHT AND VARIABLE WINDS EARLY THIS MORNING BECAME SOUTH TO SOUTHWEST 10 TO 15 KT WITH A FEW GUSTS TO AROUND 20 KT THIS AFTERNOON. THESE WINDS WILL DROP OFF TO 5 TO 10 KT AFTER SUNSET AND CONTINUE THROUGH THE NIGHT. AN APPROACHING COLD FRONT WILL REACH OUR AREA LATE TONIGHT, CROSSING THE DELAWARE VALLEY AROUND OR SHORTLY AFTER DAYBREAK. A FEW SHOWERS, AND POSSIBLY EVEN A THUNDERSTORM OR TWO, COULD ACCOMPANY THE FRONT. BUT PROBABILITIES REMAIN LOW, SO THE ONLY CURRENT HINT OF PRECIPITATION IN THE TAFS IS A VCSH IN KABE. CONDITIONS WILL REMAIN VFR THROUGH THE NIGHT, WITH THE ONLY EXCEPTION BEING AT KMIV WITH SOME PREDAWN MVFR VSBYS IN LIGHT FOG. ONCE THE FRONT CROSSES THE AREA, WINDS WILL SWING AROUND TO THE WEST AS THE PRESSURE GRADIENT TIGHTENS. BY MIDDAY EXPECT SUSTAINED WINDS TO AVERAGE AROUND 15 KT WITH GUSTS INTO THE UPPER 20S. VERY DRY AIR WILL QUICKLY INVADE THE REGION AND BRINGING CLEARING SKIES BY LATE MORNING OR EARLY AFTERNOON. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... HIGH PRESSURE CONTINUES TO MOVE SLOWLY OFF TO THE SOUTH AND EAST TODAY. WINDS HAVE BECOME SOUTHERLY 15 TO 20 KT SUSTAINED ON MOST OF OUR WATERS. SEAS ARE JUST BEGINNING TO RESPOND TO THESE WINDS, BUT, AS OF 6 PM, HAVE INCREASED TO AROUND 4 FT ON OUR OCEAN WATERS. AS THE COLD FRONT TO OUR WEST GETS CLOSER, WINDS WILL BECOME SOUTHWEST TONIGHT AND SEAS WILL CONTINUE TO BUILD. WAVEWATCH DATA INDICATES SOME POTENTIAL FOR SMALL CRAFT ADVISORY SEAS AND POSSIBLY WINDS, ESPECIALLY FOR OUR NORTHERN OCEAN WATERS TONIGHT INTO WEDNESDAY. WIND SPEEDS HAVE CONTINUED TO INCREASE AT THE NEW YORK HARBOR BUOY AND WHILE MESONET SITES RIGHT ALONG THE COAST ARE BELOW SMALL CRAFT ADVISORY CRITERIA, THERE NOW IS AN OVERLAP WINDOW WHERE IT IS OCCURRING IN OUR NORTHERN WATERS, SO WILL ISSUE A SCA FOR THEM AND CONTINUE TO MONITOR PLACES FARTHER TO THE SOUTH. ON WEDNESDAY WE WILL HAVE THE OPPOSITE PROBLEM WITH IN ALL LIKELIHOOD THE HIGHEST WINDS RIGHT ALONG THE IMMEDIATE COAST. ONCE THE FRONT CROSSES OUR AREA WEDNESDAY, WINDS WILL SHIFT TO THE WEST. THE WIND SHIFT WILL KNOCK DOWN THE SEAS ALSO. THE HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE AREA, BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... WILL CONVERT THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH 9/7... PHL 52 ONE SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 DID NOT EXCEED, POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ450-451. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES LONG TERM...GIGI AVIATION...GIGI/RPW MARINE...RPW FIRE WEATHER...HAYES CLIMATE...DRAG 000 FXUS61 KPHI 071927 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 327 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION TONIGHT...AND CROSS THE AREA WEDNESDAY MORNING. AHEAD OF THE FRONT...THERE MAY BE A FEW SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS NORTH AREAS LATE TONIGHT AND WEDNESDAY MORNING. BEHIND THE FRONT...COOLER AND LESS HUMID CONDITIONS WILL BE USHERED IN BY GUSTY WEST WINDS. HIGH PRESSURE BUILD INTO THE AREA FROM EASTERN CANADA WILL BRING DRY AND COOL CONDITIONS THURSDAY AND FRIDAY. THE HIGH WILL MOVE OFFSHORE FOR THE WEEKEND. A COLD FRONT WILL CROSS THE AREA SUNDAY...FOLLOWED BY HIGH PRESSURE FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE RETURN FLOW AROUND THE HIGH CENTERED OFFSHORE BROUGHT WARMER AND MORE HUMID CONDITIONS FOR THIS AFTERNOON WITH MARGINAL INSTABILITY. WITHOUT A FOCUS...THIS INSTABILITY SHOULD REMAIN UNTAPPED INTO THE EVENING HOURS. THE FEW CUMULUS THAT DEVELOPED WILL DISSIPATE DURING THE EVENING HOURS...AS HIGH CLOUDS CROSS THE AREA. THE SURFACE COLD FRONT LYING ACROSS THE GREAT LAKES AND WESTERN OHIO VALLEY HAS HAD COME BRIEF CONVECTION WITH IT THIS AFTERNOON...BUT THE AIRMASS AHEAD OF THE FRONT IS STILL FAIRLY STABLE. WOULD EXPECT THE CONVECTION TO BECOME A BIT BETTER ORGANIZED AS IT APPROACHES WESTERN NEW YORK STATE AND WESTERN PENNSYLVANIA THIS EVENING...AS THE IN SITU INSTABILITY IS ENHANCED BY A DECENT MID LEVEL WIND MAXIMUM. THIS ACTIVITY WILL TRY TO CROSS PENNSYLVANIA AND NEW YORK STATE DURING THE OVERNIGHT HOURS. THE AIRMASS WILL STABILIZE THIS EVENING AND THIS MAY HELP ERODE THE CONVECTION THAT MOVES EAST. THERE IS SOME INDICATION OF SOME ELEVATED INSTABILITY LATE TONIGHT ACROSS WESTERN ZONES...AND THIS COULD HELP THE CONVECTION THAT MOVES EAST TO REMAIN INTACT. BASED ON THE BEST MOISTURE AND PROJECTED INSTABILITY...LIMITED THE MENTION OF SHOWERS AND THUNDERSTORMS TO NORTH OF A KRDG-KSMQ-KMMU LINE...GENERALLY BETWEEN 0800 UTC AND 1200 UTC WEDNESDAY. THE MID LEVEL WIND MAX WEAKENS AS IT MOVES EAST. WHILE THERE MAY BE SOME GUSTINESS WITH ANY THUNDERSTORMS THAT DEVELOP...WILL NOT MENTION IT AT THIS TIME DUE TO UNCERTAINTY. FOR THE MOST PART...WITH THE SOUTHWEST FLOW AHEAD OF THE FRONT AND HIGHER DEW POINTS IN PLACE...WENT ABOVE ALL MOS NUMBERS FOR LOWS TONIGHT. IT APPEARS AS THOUGH THE FRONT ARRIVES LATE ENOUGH TONIGHT NOT TO HAVE AN INFLUENCE ON LOW TEMPERATURES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE SURFACE FRONT CROSSES THE FORECAST AREA BETWEEN ABOUT 1200 UTC AND 1700 UTC FROM WEST TO EAST. THERE SHOULD BE SOME MID LEVEL CLOUDINESS WITH THE FRONT...AND MODELS INDICATE THE BEST INSTABILITY WITH THE FRONT ACROSS NORTHERN NEW JERSEY WEDNESDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS WERE PLACED IN THE BEST INSTABILITY AND LEFT OUT OF THE REST OF THE FORECAST FOR NOW. PROBABLY NOT ENOUGH TIME FOR THE AIRMASS TO DESTABILIZE APPRECIABLY ANYWHERE ELSE FOR NOW. THE AIRMASS CHANGE OCCURS FAIRLY QUICKLY BEHIND THE FRONT...AS THE LOW LEVEL STABILIZE QUICKLY. NOT PLANNING TO MENTION ANY SHOWERS IN THE AFTERNOON BEHIND THE FRONT. THE COLD AIR ADVECTION BEHIND THE FRONT (AS THE MID LEVEL SYSTEM PUSHING IT ALONG CLOSES AS IT PASSES) SHOULD BE GOOD ENOUGH FOR STEEP LOW LEVEL LAPSE RATES AND GOOD TURBULENT MIXING. MODEL SOUNDINGS SHOW 30 TO 35 KNOTS AT THE TOP OF THE BOUNDARY LAYER FOR TRANSFER...AND THIS SHOULD TRANSLATE TO 25 TO 30 MPH WIND GUSTS IN THE AFTERNOON BEHIND THE FRONT. IN ADDITION...THE AIRMASS WILL BECOME NOTICEABLY DRIER AS DEW POINTS TUMBLE IN THE AFTERNOON. HIGHS WEDNESDAY COULD BE TRICKY AS COLD AIR ADVECTION BEGINS IN THE LATE MORNING AND EARLY AFTERNOON. THIS DOES NOT LOOK LIKE A DAY WHERE TEMPERATURES WILL BECOME STEADY OR SLOWLY FALL AFTER THE FRONT (THE SUN ANGLE IS TOO HIGH FOR THAT)...BUT TEMPERATURES MAY ONLY RISE 10 DEGREES OR SO AFTER THE FRONT PASSES. THIS WOULD PUT HIGHS CLOSER TO THE WARMER NAM MOS NUMBERS. AS THE MID LEVEL SYSTEM CLOSES OVER NORTHERN NEW ENGLAND WEDNESDAY NIGHT AND THURSDAY...WOULD EXPECT A CYCLONIC FLOW CLOUD PATTERN. THE TRAJECTORY OFF THE GREAT LAKES DOES NOT LOOK AS THOUGH IT WILL ADD CLOUDS TO NORTHERN ZONES...BUT WILL CARRY PARTLY CLOUDY SKIES WITH MOISTURE TRAPPED UNDER THE INVERSION. ELSEWHERE...SKIES SHOULD BE MOSTLY CLEAR. THE GRADIENT SHOULD REMAIN UP LONG ENOUGH TO PRECLUDE RADIATIONAL COOLING IN THE NEW AIRMASS...AND FOR THIS REASON FAVORING THE WARMER GFS MOS NUMBERS FOR LOWS. BOTH THURSDAY AND FRIDAY WILL MORE CLOSELY RESEMBLE FALL WITH CYCLONIC FLOW IN THE MID LEVELS. THE SURFACE GRADIENT SHOULD REMAIN TIGHT ENOUGH FOR GUSTY WINDS BOTH DAYS. FOR NOW...WILL INCLUDE A SLIGHT CHANCE OF SHOWERS FOR THE NORTHERN AREAS AS MID LEVEL TEMPERATURES SHOULD BE COOL ENOUGH FOR SOME CUMULUS DEVELOPMENT. ELSEWHERE...WILL KEEP CONDITIONS DRY. USED A BLEND OF MOS NUMBERS FOR HIGHS BOTH DAYS AS 850 MB TEMPERATURES SUPPORT COOLER TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE LONGER RANGE PERIOD REMAINS SIMILAR TO YESTERDAY WITH SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. THIS FORECAST PACKAGE SIDES WITHE A COMPROMISE TIMING BETWEEN THE GFS AND ECMWF, PRETTY SIMILAR TO THE CANADIAN GGEM MODEL. HIGH PRESSURE SHOULD BE BUILDING OVER OUR CWA AT THE START OF THE LONG TERM. PENDING ON A FASTER TIMING, MIN TEMPS MIGHT NEED A DOWNWARD ADJUSTMENT IN SUBSEQUENT FORECASTS ACROSS THE SOUTHEASTERN PART OF OUR CWA. BEING OF A PROGRESSIVE NATURE, THE HIGH PRESSURE SYSTEM SHOULD MOVE OFFSHORE RATHER QUICKLY. GOING WITH A CONSENSUS TIMING, WE REMOVED THE MENTION OF PCPN FOR SAT NIGHT AND HAVE SHRAS AND TSRAS ARRIVING DURING THE DAY ON SUNDAY. THE 00Z ECMWF WOULD HAVE NO PCPN TIL SUN NGT, BUT SINCE ITS UPGRADE IF ITS HAD A TIMING BIAS AT ALL, IT HAS BEEN ON THE SLOW SIDE. LOOKS LIKE THE 12Z ECMWF IS FASTER. THERE ARE INSTABILITY DIFFERENCES BETWEEN THE GFS AND ECMWF WRT TO THUNDER WITH THE GFS MORE BULLISH AND ACCEPTIVE OF IT OCCURRING IN NEARLY ALL OF OUR CWA. BECAUSE OF THE BETTER TIMING WE DID ADD THE CHANCE FOR THUNDER FOR SUNDAY DAY INTO SUNDAY EVENING. MANY DECENT LOOKING PCPN EVENTS HAVE GONE THE WAY OF THE PASSENGER PIGEON THIS WARM SEASON. THE LATEST GFS SHOWS PROMISE WITH SOME HERMINE RESIDUALS GETTING ENTRAINED INTO AND A WAVE FORMING ON THE FRONT. WE WILL HAVE TO SEE IF THIS CONTINUES IN FUTURE RUNS. CONSENSUS SOLUTION WOULD KEEP MONDAY DRY AND SOMEWHAT COOLER FOR NOW. ANOTHER REINFORCING COLD FRONT SHOULD BE APPROACHING OUR CWA ON TUESDAY. THIS ONE IS NOT FORECAST TO HAVE AS MUCH DEEP MOISTURE OR INSTABILITY, SO JUST SOME LOW GRADE SHRAS WILL BE ADDED ATTM. TEMPWISE DOES NOT LOOK LIKE MUCH EXTREMES IN EITHER DIRECTION WITH TEMPS PRETTY CLOSE TO NORMAL. ONLY DAY THAT MIGHT VERIFY WARMER WOULD BE SUNDAY IF THE CDFNT IS SLOWER IN ARRIVING. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. EXCELLENT FLYING WX CONTINUES THIS AFTERNOON AS AN AREA OF HIGH PRESSURE MOVES SLOWLY OFF TO THE SOUTH AND EAST. NOTHING MORE THAN AN FEW FAIR WEATHER CU AND SOME HIGH THIN CI ONCE AGAIN. LIGHT AND VARIABLE WINDS EARLY THIS MORNING BECAME SOUTH TO SOUTHWEST 10 TO 15 KT WITH A FEW GUSTS TO AROUND 20 KT THIS AFTERNOON. THESE WINDS WILL DROP OFF TO 5 TO 10 KT AFTER SUNSET AND CONTINUE THROUGH THE NIGHT. AN APPROACHING COLD FRONT WILL REACH OUR AREA LATE TONIGHT, CROSSING THE DELAWARE VALLEY AROUND OR SHORTLY AFTER DAYBREAK. A FEW SHOWERS, AND POSSIBLY EVEN A THUNDERSTORM OR TWO, COULD ACCOMPANY THE FRONT. BUT PROBABILITIES REMAIN LOW, SO THE ONLY CURRENT HINT OF PRECIPITATION IN THE TAFS IS A VCSH IN KABE. CONDITIONS WILL REMAIN VFR THROUGH THE NIGHT, WITH THE ONLY EXCEPTION BEING AT KMIV WITH SOME PREDAWN MVFR VSBYS IN LIGHT FOG. ONCE THE FRONT CROSSES THE AREA, WINDS WILL SWING AROUND TO THE WEST AS THE PRESSURE GRADIENT TIGHTENS. BY MIDDAY EXPECT SUSTAINED WINDS TO AVERAGE AROUND 15 KT WITH GUSTS INTO THE UPPER 20S. VERY DRY AIR WILL QUICKLY INVADE THE REGION AND BRINGING CLEARING SKIES BY LATE MORNING OR EARLY AFTERNOON. OUTLOOK... HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO THE COMING WEEKEND WITH GOOD VFR FLYING CONDITIONS. A BREEZY W TO NW FLOW WILL PERSIST THURSDAY AND FRIDAY BUT WILL BECOME LIGHT AND VARIABLE BY SATURDAY AS THE HIGH SETTLES OVER THE REGION. && .MARINE... HIGH PRESSURE CONTINUES TO MOVE SLOWLY OFF TO THE SOUTH AND EAST TODAY. WINDS HAVE BECOME SOUTHERLY 15 TO 20 KT ON OUR WATERS THIS AFTERNOON. SEAS ARE JUST BEGINNING TO RESPOND TO THESE WINDS, BUT, AS OF 2 PM, HAVE ONLY INCREASED TO AROUND 3 FT ON OUR OCEAN WATERS. AS THE COLD FRONT TO OUR WEST GETS CLOSER, WINDS WILL BECOME SOUTHWEST TONIGHT AND SEAS WILL CONTINUE TO BUILD. WAVEWATCH DATA INDICATES SOME POTENTIAL FOR SMALL CRAFT ADVISORY SEAS AND POSSIBLY WINDS, ESPECIALLY FOR OUR NORTHERN OCEAN WATERS LATER TONIGHT INTO WEDNESDAY. BUT WITH SUCH A SHORT WINDOW OF OPPORTUNITY AND A RELATIVELY LOW LEVEL OF OUR CONFIDENCE, WE WILL HOLD OFF ON ISSUING AN ADVISORY AT THIS TIME. ONCE THE FRONT CROSSES OUR AREA WEDNESDAY, WINDS WILL SHIFT TO THE WEST AND DIMINISH SLIGHTLY. THE WIND SHIFT WILL KNOCK DOWN THE SEAS ALSO. THE HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE AREA, BRINGING FAIR WEATHER AND RATHER TRANQUIL CONDITIONS THAT WILL CONTINUE INTO THE WEEKEND. && .FIRE WEATHER... WILL CONVERT THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR WEDNESDAY AFTERNOON. IT APPEARS AS THOUGH DEW POINTS SHOULD TUMBLE AFTER THE COLD FRONTAL PASSAGE. MODEL SOUNDINGS SUGGEST MIXING ROM 850 MB COULD DROP DEW POINTS INTO THE UPPER 40S AND LOWER 50S DURING THE AFTERNOON. MODEL SOUNDINGS ALSO SHOW THAT 30 TO 35 KNOTS OF WIND WILL BE AVAILABLE AT THE TOP OF THE INVERSION WEDNESDAY AFTERNOON IN THE WAKE OF THE FRONT. THIS SHOULD TRANSLATE INTO WIND GUSTS NEAR 30 MPH...ESPECIALLY DURING THE MID TO LATE AFTERNOON...WHEN DEW POINTS WILL BE AT THEIR LOWEST. EXPECTING GUSTY WINDS THURSDAY...BUT RELATIVE HUMIDITY VALUES LOOK TO BE THE LIMITING FACTOR FOR FIRE WEATHER HEADLINES THEN. && .CLIMATE... MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH LABOR DAY 9/6... PHL 51 TWO SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 LIKELY EXCEEDS! POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR PAZ060- 061-067>071. NJ...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR NJZ009- 010-012>027. DE...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR DEZ001- 002. MD...RED FLAG WARNING FROM 2 PM TO 7 PM EDT WEDNESDAY FOR MDZ008- 012-015. MARINE...NONE. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES LONG TERM...GIGI AVIATION...RPW MARINE...RPW FIRE WEATHER... CLIMATE... 000 FXUS61 KAKQ 071926 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA ISSUED BY NATIONAL WEATHER SERVICE RALEIGH NC 326 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH WEDNESDAY. A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION WEDNESDAY NIGHT. AS HIGH PRESSURE BUILDS SOUTH ACROSS THE AREA THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 320 PM TUESDAY... 18Z SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED JUST NE OF THE NC OUTER BANKS. RIDGE AXIS EXTENDS FROM SW TO NE ACROSS CENTRAL AND NE NORTH CAROLINA AND THEN OFFSHORE. A LEE TROUGH WAS ANALYZED JUST EAST OF THE BLUE RIDGE FROM W MD SOUTHWARD TO W NC. LATEST VIS SAT IMAGERY SHOWS A LARGE AREA OF FEW-SCT CUMULUS WITH BASES AROUND 5KFT. SOUTH-SOUTHEASTERLY SFC WINDS HAVE PICKED UP A BIT NORTH OF THE RIDGE AS THE SFC GRADIENT HAS TIGHTENED WITH THE APPROACHING COLD FRONT. SW WINDS AROUND 10 KTS WITH GUSTS OF 15-20 KTS THIS AFTN WILL LIGHTEN UP CONSIDERABLY AFTER SUNSET. STILL EXPECT WINDS TO REMAIN UP OVERNIGHT WHICH SHOULD PRECLUDE ANY GROUND FOG DESPITE INCREASING LOW LEVEL MOISTURE. DIURNALLY FORCED CU SHOULD WANE AROUND SUNSET WITH SOME INCREASE IN HIGH CLOUDS EXPECTED OVERNIGHT...MAINLY NORTHWEST OF KRIC. MOS GUIDANCE IN GOOD AGREEMENT AND EXPECT LOW TEMPS TO GENERALLY RANGE IN THE UPPER 60S TO LOWER 70S. -BLAES && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... AS OF 215 PM TUESDAY... WEDNESDAY AND WEDNESDAY NIGHT...AFOREMENTIONED COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA ON WEDNESDAY INTO WEDNESDAY EVENING. HOWEVER.. LACK OF OVERALL MOISTURE AND WESTERLY DOWN SLOPE FLOW SHOULD HELP KEEP THE FRONT DRY. CANNOT RULE OUT AN ISOLATED SHOWER AND/OR SPRINKLES ALONG THE FRONT... BUT WILL LEAVE OUT MENTION OF PRECIP FOR NOW GIVEN THE UNFAVORABLE SETUP AND ONLY SHOW AN INCREASE IN CLOUD COVER WITH THE FRONT (PARTLY CLOUDY SKIES). LOW LEVEL THICKNESS VALUES AREA EXPECTED TO INCREASE INTO THE 1420S FOR WEDNESDAY AFTERNOON. THIS COUPLE WITH THE DOWN SLOPE FLOW SHOULD HELP TEMPS AGAIN SOAR TO WELL ABOVE NORMAL VALUES. EXPECT HIGH TEMPS IN THE LOWER 90S... WARMEST ACROSS THE INLAND SOUTHERN REACHES OF THE CWA. IN ADDITION... IT WILL BE A BIT BREEZY ON WEDNESDAY AFTERNOON... WITH SOUNDINGS SHOWING AS MUCH AS 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER. THIS SHOULD YIELD WSW TO W WINDS OF AROUND 15 MPH SUSTAINED WITH GUSTS TO AROUND 20 TO 25 MPH. MOSTLY CLEAR SKIES ARE EXPECTED TO RETURN TO THE AREA FOR WEDNESDAY NIGHT WITH LOW TEMPS BOTTOMING OUT IN THE UPPER 50S TO LOWER 60S INLAND... WITH MID 60S NEAR THE COAST. THURSDAY THROUGH FRIDAY...CYCLONIC FLOW ALOFT WILL CONTINUE ACROSS THE AREA DURING THIS PERIOD... WITH THE MID/UPPER LOW CENTERED ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND WITH THE MAIN TROUGH AXIS EAST OF THE AREA. THIS SHOULD YIELD DRY CONDITIONS... WITH SURFACE HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT. AFTERNOON HIGHS BOTH DAYS LOOK TO RANGE FROM THE UPPER 70S ACROSS THE NORTH TO LOWER TO MID 80S ACROSS THE SOUTHWESTERN REACHES OF THE CWA. LOWS DURING THIS TIME FRAME ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S NORTH AND WEST TO MID 60S ACROSS COASTAL SECTIONS OF NORTHEASTERN NC AND SOUTHEASTERN VA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 215 PM TUESDAY... MEDIUM RANGE GUIDANCE APPEARS TO BE COMING INTO A LITTER BETTER AGREEMENT FOR THIS WEEKEND INTO EARLY NEXT WEEK. HAVE FOLLOWED CLOSER TO THE 00Z/07TH ECMWF AND THE EC ENSEMBLES... WHICH ARE PREFERRED BY HPC. FRIDAY NIGHT THROUGH SATURDAY: QUITE WEATHER IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE AT THE SURFACE BUILDS/EXTENDS INTO THE AREA FROM THE NORTH WITH MID LEVEL SHORTWAVE RIDGING BUILDING INTO THE AREA FROM THE WEST. HAVE REMOVED SLIGHT CHANCE POPS FOR SATURDAY... AS IT APPEARS THE REMNANTS OF T.S. HERMINE ARE EXPECTED TO REMAIN SOUTH OF THE AKQ CWA. THIS SHOULD LEAD TO MOSTLY CLEAR/SUNNY CONDITIONS ACROSS A GOOD PORTION OF THE AREA DURING THIS TIME... WITH LOCATIONS ACROSS NORTHEASTERN NC PROBABLY MORE PARTLY SUNNY/CLOUDY. LOW TEMPS ON SATURDAY MORNING ARE EXPECTED TO FALL INTO THE 55 TO 60 DEGREE RANGE... WITH A LOCATIONS ALONG SE COASTAL VA AND NE COASTAL NC POSSIBLY BEING A BIT WARMER... LOWER TO MID 60S. HIGHS SATURDAY ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S AS MODELS NOW SHOW AFTERNOON LOW LEVEL THICKNESS VALUES STRUGGLING TO MAKE IT TO 1400 METERS. SATURDAY NIGHT THROUGH TUESDAY: NEXT COLD FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY NIGHT AND SLOWLY MOVE INTO THE AREA ON SUNDAY. WILL CONTINUE TO GO WITH CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA WITH THIS FEATURE... AS MODELS ARE SHOWING BETTER MOISTURE RETURN AHEAD OF THIS FRONT. POPS WILL LIKELY NEED TO BE RAISED FURTHER IN LATER SHIFTS. HOWEVER... WITH MEDIUM RANGE MODELS STRUGGLING WITH THE PROGRESSION OF THE PATTERN WILL LIMITED POPS TO SUNDAY AND SUNDAY NIGHT... WHICH IS WHEN THE BEST LIFT SHOULD OCCUR ANYWAY. THE GFS IS FASTER IN CLEARING OUT THE LOW LEVEL MOISTURE AS SURFACE HIGH PRESSURE FROM THE WEST BUILDS INTO THE AREA IN EARNEST ON MONDAY... WHILE THE ECMWF SEEMS TO WASH THE FRONT OUT AND LINGER THE LOW LEVEL MOISTURE. FOR NOW WILL GO WITH HIGHS DURING THIS TIME IN THE LOWER TO MID 80S... WITH LOWS IN THE LOWER TO MID 60S... WITH PERHAPS SOME UPPER 60S NEAR THE COASTAL LOCATIONS. HOWEVER... IF THE GFS VERIFIES... WE ARE LIKELY TO WARM FOR OVERNIGHT LOWS FOR TUESDAY MORNING. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 130 PM TUESDAY... VFR CONDITIONS EXPECTED THROUGH WED AFTN. LATEST SFC ANALYSIS SHOWS HIGH PRESSURE CENTER LOCATED JUST NO OF THE NC OUTER BANKS. RIDGE AXIS EXTENDS FROM SW TO NE ACROSS CENTRAL AND NE NORTH CAROLINA AND THEN OFFSHORE. LATEST VIS SAT IMAGERY SHOWS A LARGE AREA OF FEW-SCT CU WITH BASES AROUND 5KFT...ESPECIALLY FROM THE RICHMOND AND HAMPTON ROADS AREA SOUTHWEST. SOUTH-SOUTHEASTERLY SFC WINDS HAVE PICKED UP A BIT NORTH OF THE RIDGE AS THE SFC GRADIENT HAS TIGHTENED WITH THE APPROACHING COLD FRONT. DIURNALLY FORCED CU SHOULD WANE AROUND SUNSET WITH SOME INCREASE IN HIGH CLOUDS EXPECTED OVERNIGHT...MAINLY AT KRIC AND KSBY. EXPECT WINDS TO REMAIN UP OVERNIGHT WHICH SHOULD PRECLUDE ANY GROUND FOG DESPITE INCREASING LOW LEVEL MOISTURE...ONLY EXCEPTION MIGHT BE KECG WHICH WILL BE MORE MOIST AND CLOSER TO THE SFC RIDGE. COLD FRONT DROPS SOUTH AND APPROACHES THE NORTHERN TAF SITES AFTER 18Z. LEE TROFINESS AHEAD OF THE FRONT WILL PROMOTE A MORE WESTWARD SFC WIND AND A BIT STRONGER AND MORE GUSTY. MID AND HIGH LEVEL MOISTURE WILL INCREASE DURING THE DAY SO SHOULD SEE ANOTHER ROUND OF DIURNAL CU ALONG WITH SCT-BKN ALTO/CIRRUS LEVEL CLOUDINESS. EXPECT THE FRONT TO BE MAINLY DRY SO DO NOT EXPECT AND VSBY RESTRICTIONS WITH ANY CIGS ABOVE 5KFT. LOOKING FURTHER AHEAD...GENERALLY VFR CONDITIONS ARE EXPECTED FROM LATE WED INTO FRIDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH AND WEST. A WARM FRONT WILL APPROACH THE REGION FROM THE SOUTHWEST DURING THE WEEKEND WHICH COULD BRING A CHANCE OF SCT MAINLY AFTN/EVEN SHOWERS OR THUNDERSTORMS. -BLAES && .MARINE... AS OF 320 PM TUESDAY... ...SMALL CRAFT ADVISORY IN EFFECT IN THE CHESAPEAKE BAY FROM SMITH POINT TO NEW POINT COMFORT VA... LATEST ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED JUST NE OF THE NORTHERN OUTER BANKS. A RIDGE AXIS EXTENDS SW FROM THE HIGH CENTER ACROSS NORTHEAST NC. LATEST MARINE OBS INDICATE MAINLY S TO SSW WINDS AT 10-14KTS ACROSS THE NORTHERN AND CENTRAL CHES BAY WITH GUSTS OF AROUND 15 KTS...OCCASIONALLY APPROACHING 20 KTS. WINDS ARE LIGHTER FURTHER SOUTH IN CLOSER PROXIMITY TO THE SFC RIDGE. PATTERN TONIGHT OF WARM ADVECTION ON THE WESTERN SIDE OF A SHIFTING HIGH CENTER SUGGESTS WINDS TO REMAIN UP TONIGHT. NAM/SREF GUIDANCE STILL SHOWS 15-20KTS OF S/SW FLOW AHEAD OF THE FRONT TONIGHT. WILL MAINTAIN MINIMAL SCA CRITERIA OVER THE CEN/NRN PTNS OF CHES BAY. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA INTO A DEVELOPING LEE TROUGH...EXPECT A WIND SHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY DELTA TEMPS AROUND 12C WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. EXPECT JUST A BRIEF PERIOD OF THESE CONDITIONS OVERNIGHT. -BLAES && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EDT WEDNESDAY FOR ANZ630-631. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BSD LONG TERM...BSD AVIATION...BLAES MARINE...BLAES 000 FXUS61 KLWX 071924 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 324 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE COAST THROUGH TONIGHT. A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO WEDNESDAY....BRINGING BREEZY CONDITIONS. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND PERSIST INTO THE WEEKEND. A COLD FRONT WILL IMPACT THE REGION IN THE SUNDAY TIMEFRAME...WHICH WILL BE FOLLOWED BY MORE HIGH PRESSURE. && .NEAR TERM /THROUGH WEDNESDAY/... HIPRES WILL CONTINUE TO PUSH OFF THE MID-ATLANTIC COAST TNGT AS A COLD FRONT OVER THE MIDWEST PUSHES THRU THE OH VLY THIS EVE AND ACROSS THE CENTRAL APPALACHIANS LATE TONIGHT. THE FRONT SHOULD BEGIN TO ENTER THE WRN SLOPES OF THE ALLEGHENY FRONT AROUND DAYBREAK WED MRNG. 12Z MODEL RUNS CONTINUE TO SHOW PRECIP BREAKING UP AS IT CROSSES THE CENTRAL APPALACHIANS. HOWEVER...THE 12Z NAM NOW SHOWS PRECIP MAKING IT INTO THE ENTIRE CWA. THINK THE 12Z NAM IS OVERDONE GIVEN THE BEST DYNAMICS WILL BE SITUATED CLOSER TO THE UPPER LOW OVER THE NORTHEAST STATES...AND DOWNSLOPING FLOW WILL HINDER LIFT EAST OF THE ALLEGHENY FRONT. WHILE SOME OF THE PERIPHERAL MOISTURE STREAMING NORTHEAST FROM HERMINE MAY MEET UP WITH THE FRONTAL BOUNDARY TOMORROW...IT SHOULD REMAIN FARTHER SOUTH AND NOT IMPACT OUR AREA. THEREFORE CANNOT RULE OUT A SHOWER LATE TNGT/ERY MRNG ACROSS THE FAR WRN ZONES...BUT REMAIN DRY FARTHER TO THE EAST. THE FRONT WILL CROSS THE I-95 CORRIDOR IN THE MRNG...AND PUSH THRU LOWER SRN MD BY THE ERY AFTN. AFTER AN INCREASE IN MID TO UPPER CLOUDS ASSOCIATED WITH THE FROPA IN THE MRNG...SKIES WILL CLEAR OUT BEHIND THE FRONT AS THE ENTIRE COLUMN QUICKLY DRIES OUT. GUSTY WESTERLY WINDS ARE EXPECTED TO INCREASE TO 15-20 MPH WITH GUSTS TO 30 MPH POSSIBLE DURING THE AFTN. SEE FIRE SECTION FOR DISCUSSION OF FIRE THREAT ON WED. DAYTIME HIGHS WED WILL RANGE FROM THE 70S ACROSS THE RIDGE TOPS TO MU80S EAST OF THE BLUE RIDGE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT IN THE WAKE OF THE DAYTIME FROPA WITH DOWNSLOPING WLY FLOW ENSURING DRY AND CLEAR CONDITIONS /ANY SKY COVER WOULD BE HIGH CLOUDS/. COLD AIR ADVECTION TO PREVENT DECOUPLING...MIN TEMPS AROUND 60F EAST OF I-95...LOW TO MID 50S INLAND...LOW 40S FOR HIGH ELEVATIONS OUT WEST. THURSDAY THROUGH FRIDAY NIGHT...UPPER LOW DRIFTS EAST ACROSS NEW ENGLAND AS A RIDGE AMPLIFIES AS IT BUILDS EAST ACROSS THE MIDWEST. THIS WILL MAINTAIN DRY NWLY FLOW WITH SUNNY/CLEAR CONDITIONS MAX TEMPS LIMITED TO UPPER 70S /JUST BELOW NORMAL/. MIN TEMPS A FEW DEGREES BELOW NORMAL BOTH NIGHTS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A COLD FRONT ASSOCIATED WITH A LOW OVER NRN ONTARIO LOOKS TO IMPACT THE MID ATLANTIC IN THE SUNDAY TIMEFRAME. WENT WITH A BLEND OF THE QUICKER GFS AND SLOWER ECMWF FOR A SUNDAY AFTERNOON/EVENING FROPA ATTM. REMNANT MOISTURE FROM HERMINE SHOULD BE PICKED UP FROM THIS SYSTEM...SO HOPEFULLY THIS WILL BE A MORE WIDESPREAD RAIN EVENT...THOUGH A WEST TO EAST FROPA WOULD SUGGEST SCATTERING PRECIP AS IT PASSES THE APPALACHIANS. MORE HIGH PRESSURE POST FROPA. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS TNGT AND WED. S-SW WINDS GUSTING TO 15 KT THRU THE REST OF THE AFTN WILL DIMINISH TOWARD SUNSET. A COLD FRONT WILL MOVE THRU THE TERMINALS WED MRNG. FROPA WILL BE MARKED BY A WINDSHIFT FROM THE WEST. DURING THE LATE MRNG INTO THE AFTN...SUSTAINED WINDS WILL INCREASE TO AROUND 15 KT...WITH GUSTS 20-25 KT POSSIBLE. POST FROPA WLY/NWLY FLOW WITH VFR CONDS WED NIGHT INTO THE WEEKEND. NEXT COLD FRONT IN THE SUNDAY TIMEFRAME. && .MARINE... SCA REMAINS IN EFFECT FOR TNGT AND WED. WINDS SHOULD RELAX A BIT THIS EVE IN AREAS NOT PRONE TO SLY CHANNELING /E.G. CENTRAL AND NRN TIDAL POTOMAC AND NRN MOST CHSPK BAY/ WHERE THE SCA IS NOT IN EFFECT FOR TNGT. A COLD FRONT WILL MOVE THRU THE WATERS LATE WED MRNG INTO THE ERY AFTN. WIDESPREAD GUSTS OF 20 KT EXPECTED BEHIND THE FRONT. EXTENDED SCA THROUGH WEDNESDAY NIGHT FOR THE MD BAY/SRN TIDAL POTOMAC AND EASTERN TRIBUTARIES /NOT PATAPSCO OR PAX RIVER/ WITH POST FROPA WLY/NWLY COOL FLOW MIXING DOWN OVER THE WARM WATER. NEAR SCA NWLY FLOW THEN PERSISTS INTO THE WEEKEND WITH AND UPPER LOW OVER NEW ENGLAND...SCA/S MORE LIKELY IF WIND IS ABLE TO VEER TO NLY AND CHANNEL DOWN THE BAY. && .FIRE WEATHER... EXTENDED DRY CONDITIONS HAVE RESULTED IN VERY LOW FUEL MOISTURE...GENERALLY BELOW SIX PERCENT. DRY CONDITIONS ARE EXPECTED TO PERSIST FOR MOST LOCATIONS THROUGH THE REST OF THE WEEK. PLEASE NOTE- BURNING BAN FOR ERN WV PANHANDLE WENT INTO EFFECT THIS MRNG AND WILL CONTINUE UNTIL FURTHER NOTICE. A COLD FRONT WILL MOVE THRU THE REGION LATE TNGT INTO WED. BREEZY AND DRY CONDITIONS ARE EXPECTED BEHIND THE FRONT ON WED. RED FLAG CONDITIONS ARE POSSIBLE ON WED WITH SUSTAINED WINDS APPROACHING 20 MPH AND MIN AFTN RH VALUES BETWEEN 25-30 PERCENT COMBINED WITH THE ALREADY LOW FUEL MOISTURE. AFTER TALKING TO STATE FIRE OFFICIALS...A A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MOST OF THE CWFA...WITH THE EXCLUSION OF THE NRN PIEDMONT AND CENTRAL FOOTHILLS IN VA /WHERE WINDS WILL LIGHTER/. WILL COORDINATE WITH STATE FIRE OFFICIALS IN THE MRNG WHEN WRNG HEADLINE DECISIONS ARE MADE. NWLY FLOW WILL CONTINUE FOR THURSDAY AND FRIDAY...MAINTAINING AN ENHANCED FIRE WX THREAT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR DCZ001. MD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR MDZ003>007-009>011-013-014-016>018-501-502. VA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR VAZ021-025>031-038>040-042-051>054-501-502. WV...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR WVZ050>055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ531>534- 537-539>541-543. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ530- 535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM TO 8 PM EDT WEDNESDAY FOR ANZ535-536-538-542. SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO 6 AM EDT THURSDAY FOR ANZ530. && $$ SYNOPSIS...BAJ NEAR TERM...JRK SHORT TERM...BAJ LONG TERM...BAJ AVIATION...BAJ/JRK MARINE...BAJ/JRK FIRE WEATHER...JRK/BAJ 000 FXUS61 KPBZ 071852 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 252 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING A CHANCE OF SHOWERS. THIS FRONT WILL BRING MUCH COOLER TEMPERATURES INTO LATE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... COLD FRONT ACROSS NORTHWEST OHIO WILL WORK ACROSS REGION THIS EVENING WITH A SCATTERED BAND OF SHOWERS AND A FEW THUNDERSTORMS EXPECTED. BEHIND THE FRONT MUCH COOLER AIR WILL ARRIVE BY MORNING WITH LOWS IN THE MID TO UPPER 50S. WITH NORTHWEST WINDS WEDNESDAY EXPECT SOME CLOUDS ACROSS THE NORTHERN TIER OFF THE LAKES AND POSSIBLY A SPRINKLE. TEMPERATURES WILL BE MUCH COOLER WITH UPPER 60S NORTH UNDER CLOUDS TO MID 70S SOUTH WHERE SUNSHINE PREVAILS. SPS ISSUED FOR ELEVATED FIRE DANGER INTO THIS EVENING BEFORE RELATIVE HUMIDITY RISES AS FRONT APPROACHES. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL LOW WILL SPIN ACROSS THE NORTHERN LAKES TO NEW ENGLAND THROUGH THE PERIOD WITH NORTHWEST FLOW TO DOMINATE WEATHER. EXPECT CLOUDS OFF OF THE LAKES TO BE ACROSS THE NORTH IN A DIURNAL FASHION WITH A SPRINKLE OR TWO POSSIBLE FAR NORTH. OTHERWISE SEASONABLY COOL THROUGH THE PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. CLOSE TO HPC PROGS THROUGH PERIOD. AFTER FRONTAL PRECIP MOVES OUT FAIR AND DRY BEYOND THOUGH END OF FORECAST PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... WINDS S/SW AT 10-14KT WITH GUSTS TO 25KT THIS AFTN. CLOUDS WILL INCREASE BY EARLY THIS EVENING AS A COLD FRONT APPROACHES. EXPECT A 2-4 HOUR PERIOD OF SHWRS ALONG THE BOUNDARY...THUS HAVE INCLUDED VFR SHWRS FROM 01-04Z AT ZZV...03-07Z AT HLG/FKL/AGC/PIT/BVI...AND 06-09Z FOR LBE/MGW/DUJ. ANY RESTRICTIONS WILL BE VERY SHORT LIVED AND NOT INCLUDED IN THE TERMINALS. LINGERING STRATOCUMULUS WILL PREVAIL WEDNESDAY IN THE WAKE OF THE COLD FRONT...WITH AN ISOLATED SHWR POSSIBLE NORTH OF PIT...WITH SOME MVFR RESTRICTIONS POSSIBLE. GUSTY WEST WINDS 10-15KTS GUSTING 20-25KTS MIXING DOWN BY EARLY AFTERNOON. VFR CONDITIONS AREA WIDE ARE EXPECTED THURSDAY/FRIDAY UNDER HIGH PRESSURE...WITH A CHANCE OF SHWRS AND RESTRICTIONS RETURNING FOR SATURDAY AND SUNDAY AS THE NEXT FRONTAL SYSTEM IS PROGGED TO AFFECT THE AREA. CLEARING MONDAY AND BEYOND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KAKQ 071750 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA ISSUED BY NATIONAL WEATHER SERVICE RALEIGH NC 145 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH WEDNESDAY. A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION WEDNESDAY NIGHT. AS HIGH PRESSURE BUILDS SOUTH ACROSS THE AREA THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST SFC ANALYSIS DEPICTS A HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST RIDGING SOUTHWEST INTO FAR SE VA AND NE NC. LATEST VIS SAT IMAGERY DEPICTS CLEAR SKIES WITH THE EXCEPTION OF A SMALL BIT OF REMNANT STRATO-CU WEST OF SOUTH HILL. MORNING ROABS FROM KGSO/KRNK/KLWX/KWAL DEPICT A RATHER DRY AIR MASS WITH SOME LOW LEVEL MOISTURE TO THE SW ASSOCIATED WITH THE STRATO-CU AND SOME MID LEVEL MOISTURE AT KLWX. EXPECT SUNNY SKIES TODAY WITH 500 HPA RIDGE EXTENDING NE INTO THE REGION. AS SFC RIDGE AXIS SHIFTS SOUTH TODAY...LOW LEVEL FLOW WILL BECOME MORE S/SW LATE TODAY. LOW LEVEL THICKNESS VALUES GENERALLY SUPPORT INLAND HIGH TEMPS IN THE UPPER 80S TO LOWER 90S WITH COOLER TEMP NEAR THE WATER. DEW POINTS WILL BECOME TO INCREASE ACROSS FAR S VA AND NE NC LATE TODAY WITH THE VEERING LOW LEVEL FLOW. MAINLY CLEAR SKIES EXPECTED TONIGHT WITH SOME INCREASE IN HIGH CLOUDS ACROSS N AND NW ZONES AS A COLD FRONT APPROACHES THE REGION FRO THE NW. WARM ADVECTION IN THE LOW LEVELS AND A MOISTENING BOUNDARY LAYER WILL KEEP MINS UP FROM PAST MORNINGS. EXPECT LOWS IN THE MID TO UPPER 60S EXCEPT NEAR 70 ALONG THE COAST. -BLAES && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... WEDNESDAY... HIGH PRESSURE WILL BE ORIENTED WELL EAST OF THE REGION BY WEDNESDAY AFTERNOON AS WEAK (MAINLY DRY) SURFACE COLD FRONT CROSSES THE REGION LATE IN THE DAY. STILL NOT VERY OPTIMISTIC ABOUT THE CHANCE OF RAIN ACROSS AKQ CWA WEDNESDAY AFTERNOON/EVENING WITH THE FROPA AS THE FRONT LOOKS MOISTURE- STARVED AND LTL IN THE WAY OF LIFT TO SPEAK OF THRU THE PERIOD. WILL CONTINUE TO ADVERTISE DRY FORECAST AND INCREASING CLD TREND FOR THE LTR AFTERNOON/ERY EVENING HOURS DUE TO WEAK LOW-LEVEL CONVERGENCE. HIGH WILL BE IN THE UPR 80S/LOW 90S ONCE AGAIN WITH THE NORMALLY WARMER SPOTS REACHING THE MID-90S....MOST LIKELY ACROSS THE SOUTHERN TIER OF THE CWA. CLEARING SKIES WED NIGHT AS FRONT SINKS JUST SOUTH OF THE CWA. STAYED JUST BELOW COOLER ENVELOPE OF GUIDANCE (MAV) U50S- L60S MOST ZONES. THURSDAY... MID-ATLANTIC REGION WILL BE BETWEEN UPR RIDGE OVER THE SOUTHEASTERN CONUS AND THE NORTHERN STREAM UPR LOW...WHICH SHOULD BE ORIENTED OVER NORTHERN NEW ENGLAND BY THURSDAY MORNING. DESPITE MOSTLY SUNNY CONDITIONS...RESULTANT NW FLOW SHOULD ALLOW FOR A BIT OF COOLDOWN ON THURSDAY...ESPECIALLY NORTH AND EAST. EXPECT MAXIMA TO FALL BACK INTO THE U70S-L/M80S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE LONGWAVE PATTERN LATE THIS WEEK FEATURES AN UPPER RIDGE AXIS OVER THE MID AND UPPER MISSISSIPPI VALLEY...AND AN UPPER LOW OVER FAR NORTHERN NEW ENGLAND/ATLANTIC CANADA WITH ITS ASSOCIATED AXIS EXTENDING TO THE SOUTHEAST OVER THE ATLANTIC. THIS WILL PLACE THE MID ATLANTIC IN A SUBSIDENCE REGION WITH DRY CONDITIONS EXPECTED THURSDAY NIGHT AND FRIDAY. A BACKDOOR COLD FRONT SETTLES ACROSS THE REGION AS IT BECOME PARALLEL TO THE UPPER FLOW. COOL N TO NE FLOW BEHIND THE FRONT WILL PRODUCE MAXIMUM TEMPERATURES IN THE UPPER 70S OVER THE EASTERN SHORE...WHICH WILL GRADUALLY INCREASE TO THE MID 80S OVER THE FAR SOUTHERN INTERIOR COUNTIES. GFS/ECMWF INCREASE MOISTURE ALONG THE FRONT FRIDAY NIGHT AND SATURDAY ASSOCIATED WITH THE REMNANTS OF HERMINE. INCLUDED SLIGHT CHANCE/CHANCE POPS IN THE SOUTHERN ZONES TO ACCOUNT FOR THIS...BUT DID NOT GO ANY HIGHER BASED ON DRY ANTECEDENT CONDITIONS. THE STATIONARY FRONT LIFTS THROUGH THE REGION AS A WARM FRONT SATURDAY NIGHT AND SUNDAY WITH A COLD FRONT APPROACHING EARLY NEXT WEEK. STAYED WITH SLIGHT CHANCE POPS AGAIN BASED ON DRY CONDITIONS AND MODEL DISAGREEMENT...DRY ECMWF AND RELATIVELY WETTER GFS. HIGH TEMPERATURES SHOULD RETURN TO THE MID AND UPPER 80S WITH SLIGHTLY COOLER READINGS OVER THE EASTERN SHORE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS EXPECTED THROUGH WED AFTN. LATEST SFC ANALYSIS SHOWS HIGH PRESSURE CENTER LCOATED JUST NO OF THE NC OUTER BANKS. RIDGE AXIS EXTENDS FROM SW TO NE ACROSS CENTRAL AND NE NORTH CAROLINA AND THEN OFFSHORE. LATEST VIS SAT IMAGERY SHOWS A LARGE AREA OF FEW-SCT CU WITH BASES AROUND 5KFT...ESPECIALLY FROM THE RICHMOND AND HAMPTONS ROADS AREA SOUTHWEST. SOUTH-SOUTHEASTERLY SFC WINDS HAVE PICKED UP A BIT NORTH OF THE RIDGE AS THE SFC GRADIENT HAS TIGHTENED WITH THE APPROACHING COLD FRONT. DIURNALLY FORCED CU SHOULD WANE AROUND SUNSET WITH SOME INCREASE IN HIGH CLOUDS EXPECTED OVERNIGHT...MAINLY AT KRIC AND KSBY. EXPECT WINDS TO REMAIN UP OVERNIGHT WHICH SHOULD PRECLUDE ANY GROUND FOG DESPITE INCREASING LOW LEVEL MOISTURE...ONLY EXCEPTION MIGHT BE KECG WHICH WILL BE MORE MOIST AND CLOSER TO THE SFC RIDGE. COLD FRONT DROPS SOUTH AND APPROACHES THE NORTHERN TAF SITES AFTER 18Z. LEE TROFINESS AHEAD OF THE FRONT WILL PROMOTE A MORE WESTWARD SFC WIND AND A BIT STRONGER AND MORE GUSTY. MID AND HIGH LEVEL MOISTURE WILL INCREASE DURING THE DAY SO SHOULD SEE ANOTHER ROUND OF DIURNAL CU ALONG WITH SCT-BKN ALTO/CIRRUS LEVEL CLOUDINESS. EXPECT THE FRONT TO BE MAINLY DRY SO DO NOT EXPECT AND VSBY RESTRICTIONS WITH ANY CIGS ABOVE 5KFT. LOOKING FURTHER AHEAD...GENERALLY VFR CONDITIONS ARE EXPECTED FROM LATE WED INTO FRIDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH AND WEST. A WARM FRONT WILL APPROACH THE REGION FROM THE SOUTHWEST DURING THE WEEKEND WHICH COULD BRING A CHANCE OF SCT MAINLY AFTN/EVEN SHOWERS OR THUNDERSTORMS. -BLAES && .MARINE... HIGH PRESSURE REMAINS CENTERED OFF THE DELMARVA COAST. THE RIDGE AXIS WHICH EXTENDS SOUTHWESTWARD INTO NE NC THIS AFTN WILL SHIFT SOUTHWARD THROUGH TONIGHT. A COLD FRONT APPROACHES FROM THE NW EARLY ON WED AND PUSHES THROUGH THE MID ATLANTIC LATER ON WED. BEST FORCING AND MOISTURE REMAIN NORTH OF THE AREA SO EXPECT NO PRECIP AND RESTRICTION TO VSBY. WINDS CURRENTLY RUNNING SSW AT 8-15KTS ACROSS THE CENTRAL AND NORTHERN BAY WITH SOME GUSTS ARND 20 KTS. WINDS LIGHTER CLOSER TO THE RIDGE AXIS IN THE SOUTHERN BAY AND COASTAL NC. NAM/SREF GUIDANCE CONTINUE TO SHOW 15-20KTS OF S/SW FLOW AHEAD OF THE FRONT TONIGHT WITH MINIMAL SCA CRITERIA OVER THE CEN/NRN PTNS OF CHES BAY. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA...EXPECT A WINDSHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY (WATER SFC-900 MB DELTA TEMPS AROUND 12C) WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. PREVIOUS DISCUSSION NOTED THAT DIURNAL MIXING OVER LAND THIS TIME OF YEAR TENDS TO DISRUPT THE WELL-MIXED ENVIRONMENT OVER WATER DURING THE DAY...ESPECIALLY WITH FULL SUN...AND AS SUCH ANY SCA CONDITIONS REALIZED WED NIGHT/EARLY THU AM WOULD MORE THAN LIKELY SUBSIDE AFTER SUNRISE ON THU. HOWEVER...GIVEN THE CONTINUED COOL AIR ALOFT (WATER SFC-900 MB DELTA T`S ~12C)...COULD SEE ANOTHER NRLY SURGE (MORE MARGINAL SCA CONDITIONS) THU NIGHT THROUGH DAYBREAK FRI. -BLAES/BKH && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EDT WEDNESDAY FOR ANZ630-631. && $$ SYNOPSIS..BLAES NEAR TERM...BLAES/MAM SHORT TERM...MAM/JDM LONG TERM...AJZ AVIATION...BLAES MARINE...BLAES/BKH 000 FXUS61 KAKQ 071727 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA ISSUED BY NATIONAL WEATHER SERVICE RALEIGH NC 125 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH WEDNESDAY. A DRY COLD FRONT WILL MOVE SOUTH ACROSS THE REGION WEDNESDAY NIGHT. AS HIGH PRESSURE BUILDS SOUTH ACROSS THE AREA THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST SFC ANALYSIS DEPICTS A HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST RIDGING SOUTHWEST INTO FAR SE VA AND NE NC. LATEST VIS SAT IMAGERY DEPICTS CLEAR SKIES WITH THE EXCEPTION OF A SMALL BIT OF REMNANT STRATO-CU WEST OF SOUTH HILL. MORNING ROABS FROM KGSO/KRNK/KLWX/KWAL DEPICT A RATHER DRY AIR MASS WITH SOME LOW LEVEL MOISTURE TO THE SW ASSOCIATED WITH THE STRATO-CU AND SOME MID LEVEL MOISTURE AT KLWX. EXPECT SUNNY SKIES TODAY WITH 500 HPA RIDGE EXTENDING NE INTO THE REGION. AS SFC RIDGE AXIS SHIFTS SOUTH TODAY...LOW LEVEL FLOW WILL BECOME MORE S/SW LATE TODAY. LOW LEVEL THICKNESS VALUES GENERALLY SUPPORT INLAND HIGH TEMPS IN THE UPPER 80S TO LOWER 90S WITH COOLER TEMP NEAR THE WATER. DEW POINTS WILL BECOME TO INCREASE ACROSS FAR S VA AND NE NC LATE TODAY WITH THE VEERING LOW LEVEL FLOW. MAINLY CLEAR SKIES EXPECTED TONIGHT WITH SOME INCREASE IN HIGH CLOUDS ACROSS N AND NW ZONES AS A COLD FRONT APPROACHES THE REGION FRO THE NW. WARM ADVECTION IN THE LOW LEVELS AND A MOISTENING BOUNDARY LAYER WILL KEEP MINS UP FROM PAST MORNINGS. EXPECT LOWS IN THE MID TO UPPER 60S EXCEPT NEAR 70 ALONG THE COAST. -BLAES && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... WEDNESDAY... HIGH PRESSURE WILL BE ORIENTED WELL EAST OF THE REGION BY WEDNESDAY AFTERNOON AS WEAK (MAINLY DRY) SURFACE COLD FRONT CROSSES THE REGION LATE IN THE DAY. STILL NOT VERY OPTIMISTIC ABOUT THE CHANCE OF RAIN ACROSS AKQ CWA WEDNESDAY AFTERNOON/EVENING WITH THE FROPA AS THE FRONT LOOKS MOISTURE- STARVED AND LTL IN THE WAY OF LIFT TO SPEAK OF THRU THE PERIOD. WILL CONTINUE TO ADVERTISE DRY FORECAST AND INCREASING CLD TREND FOR THE LTR AFTERNOON/ERY EVENING HOURS DUE TO WEAK LOW-LEVEL CONVERGENCE. HIGH WILL BE IN THE UPR 80S/LOW 90S ONCE AGAIN WITH THE NORMALLY WARMER SPOTS REACHING THE MID-90S....MOST LIKELY ACROSS THE SOUTHERN TIER OF THE CWA. CLEARING SKIES WED NIGHT AS FRONT SINKS JUST SOUTH OF THE CWA. STAYED JUST BELOW COOLER ENVELOPE OF GUIDANCE (MAV) U50S- L60S MOST ZONES. THURSDAY... MID-ATLANTIC REGION WILL BE BETWEEN UPR RIDGE OVER THE SOUTHEASTERN CONUS AND THE NORTHERN STREAM UPR LOW...WHICH SHOULD BE ORIENTED OVER NORTHERN NEW ENGLAND BY THURSDAY MORNING. DESPITE MOSTLY SUNNY CONDITIONS...RESULTANT NW FLOW SHOULD ALLOW FOR A BIT OF COOLDOWN ON THURSDAY...ESPECIALLY NORTH AND EAST. EXPECT MAXIMA TO FALL BACK INTO THE U70S-L/M80S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE LONGWAVE PATTERN LATE THIS WEEK FEATURES AN UPPER RIDGE AXIS OVER THE MID AND UPPER MISSISSIPPI VALLEY...AND AN UPPER LOW OVER FAR NORTHERN NEW ENGLAND/ATLANTIC CANADA WITH ITS ASSOCIATED AXIS EXTENDING TO THE SOUTHEAST OVER THE ATLANTIC. THIS WILL PLACE THE MID ATLANTIC IN A SUBSIDENCE REGION WITH DRY CONDITIONS EXPECTED THURSDAY NIGHT AND FRIDAY. A BACKDOOR COLD FRONT SETTLES ACROSS THE REGION AS IT BECOME PARALLEL TO THE UPPER FLOW. COOL N TO NE FLOW BEHIND THE FRONT WILL PRODUCE MAXIMUM TEMPERATURES IN THE UPPER 70S OVER THE EASTERN SHORE...WHICH WILL GRADUALLY INCREASE TO THE MID 80S OVER THE FAR SOUTHERN INTERIOR COUNTIES. GFS/ECMWF INCREASE MOISTURE ALONG THE FRONT FRIDAY NIGHT AND SATURDAY ASSOCIATED WITH THE REMNANTS OF HERMINE. INCLUDED SLIGHT CHANCE/CHANCE POPS IN THE SOUTHERN ZONES TO ACCOUNT FOR THIS...BUT DID NOT GO ANY HIGHER BASED ON DRY ANTECEDENT CONDITIONS. THE STATIONARY FRONT LIFTS THROUGH THE REGION AS A WARM FRONT SATURDAY NIGHT AND SUNDAY WITH A COLD FRONT APPROACHING EARLY NEXT WEEK. STAYED WITH SLIGHT CHANCE POPS AGAIN BASED ON DRY CONDITIONS AND MODEL DISAGREEMENT...DRY ECMWF AND RELATIVELY WETTER GFS. HIGH TEMPERATURES SHOULD RETURN TO THE MID AND UPPER 80S WITH SLIGHTLY COOLER READINGS OVER THE EASTERN SHORE. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... SURFACE OBS SHOWING VFR CONDITIONS WITH LIGHT WINDS AND CLEAR SKIES. BASED ON OB TRENDS THUS FAR OVERNIGHT...SUSPECT THE LIGHT GRADIENT S/SW SFC FLOW WILL CONTINUE OVER MOST TAF SITES...WITH THE PSBL EXCEPTION OF KECG (CLOSER PROXIMITY TO RIDGE AXIS). GRANTED...SPEEDS SHOULD CONTINUE TO AVG AOB 5 KTS...HOWEVER THIS WILL LIKELY BE SUFFICIENT TO PRECLUDE THE DVLPMNT OF SHALLOW RADIATION FOG. AGAIN THINK KECG HAS THE BEST CHANCE TO SEE DECOUPLING SFC WINDS AGAIN TONIGHT...AND THUS HAVE CONTINUED TO ADVERTISE A PERIOD OF IFR VSBYS IN FOG DURING THE PRE-DAWN HOURS OVER THIS SITE. HEATING AND MIXING WILL CLEAR ANY FOG BY 12Z...AS VFR CONDITIONS WILL ONCE AGAIN BE PRESENT THROUGH OUT THE AREA. A WEAK COLD FRONT APPROACHES THE AREA ON WED BRINGING IN MORE CLOUDS...A CHANCE FOR SOME SPRINKLES..AND A WIND SHIFT TO THE NW. && .MARINE... HIGH PRESSURE REMAINS CENTERED OFF THE DELMARVA COAST. THE RIDGE AXIS WHICH EXTENDS SOUTHWESTWARD INTO NE NC THIS AFTN WILL SHIFT SOUTHWARD THROUGH TONIGHT. A COLD FRONT APPROACHES FROM THE NW EARLY ON WED AND PUSHES THROUGH THE MID ATLANTIC LATER ON WED. BEST FORCING AND MOISTURE REMAIN NORTH OF THE AREA SO EXPECT NO PRECIP AND RESTRICTION TO VSBY. WINDS CURRENTLY RUNNING SSW AT 8-15KTS ACROSS THE CENTRAL AND NORTHERN BAY WITH SOME GUSTS ARND 20 KTS. WINDS LIGHTER CLOSER TO THE RIDGE AXIS IN THE SOUTHERN BAY AND COASTAL NC. NAM/SREF GUIDCANCE CONTINUE TO SHOW 15-20KTS OF S/SW FLOW AHEAD OF THE FRONT TONIGHT WITH MINIMAL SCA CRITERIA OVER THE CEN/NRN PTNS OF CHES BAY. AS FRONT MOVES SOUTH ACROSS THE MARINE AREA...EXPECT A WINDSHIFT TO NORTHERLY LATE IN THE DAY WED AND OVERNIGHT WED. SFC GRADIENT IS MODEST BUT STRENGTHENING OVER-WATER INSTABILITY (WATER SFC-900 MB DELTA TEMPS AROUND 12C) WOULD SUPPORT A WINDOW OF 18-25 KT WINDS BTWN MIDNIGHT AND 6 AM THU OVER CHES BAY AND THE CSTL WATERS N OF THE VA/NC BORDER. PREVIOUS DISCUSSION NOTED THAT DIURNAL MIXING OVER LAND THIS TIME OF YEAR TENDS TO DISRUPT THE WELL-MIXED ENVIRONMENT OVER WATER DURING THE DAY...ESPECIALLY WITH FULL SUN...AND AS SUCH ANY SCA CONDITIONS REALIZED WED NIGHT/EARLY THU AM WOULD MORE THAN LIKELY SUBSIDE AFTER SUNRISE ON THU. HOWEVER...GIVEN THE CONTINUED COOL AIR ALOFT (WATER SFC-900 MB DELTA T`S ~12C)...COULD SEE ANOTHER NRLY SURGE (MORE MARGINAL SCA CONDITIONS) THU NIGHT THROUGH DAYBREAK FRI. -BLAES/BKH && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EDT WEDNESDAY FOR ANZ630-631. && $$ SYNOPSIS..BLAES NEAR TERM...BLAES/MAM SHORT TERM...MAM/JDM LONG TERM...AJZ AVIATION...BKH MARINE...BLAES/BKH 000 FXUS61 KPBZ 071642 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1242 PM EDT TUE SEP 7 2010 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING A CHANCE OF SHOWERS. THIS FRONT WILL ALSO RESULT IN TEMPERATURES GOING FROM ABOVE NORMAL THIS AFTERNOON TO BELOW NORMAL FOR THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... SUNSHINE WITH QUITE WARM TEMPERATURES THIS AFTERNOON AHEAD OF A COLD FRONT TO PASS THE REGION TONIGHT. RAISED MAX TEMPS A DEGREE BUT ALSO RAISED DEW POINTS MOISTURE IS ADVECTING NORTHEAST ACROSS OHIO. CURRENT MODEL ANALYSIS INDICATES THAT MOST OF THE PRECIP POTENTIAL WILL BE CONFINED TO THE AREA OF BEST FRONTOGENESIS. THEREFORE...WILL CONFINE BETTER POPS TO A STRIP ALONG THE BOUNDARY...WITH LITTLE POTENTIAL FURTHER AHEAD OF IT. BEST TIMING AT THIS POINT LOOKS LIKE FROPA BETWEEN 02-08Z FROM WEST TO EAST. ALSO...ENOUGH INSTABILITY WITH THIS BOUNDARY TO MENTION THUNDER ALONG IT. ON INCREASING SOUTHWEST FLOW...TEMPS SHOULD RAMP UP INTO THE LOW TO MID 80S THIS AFTERNOON. WILL NEED TO MONITOR FIRE WEATHER POTENTIAL...AS DESCRIBED BELOW...FOR THIS AFTERNOON. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... FOR WEDNESDAY...WRAP AROUND LOW LEVEL MOISTURE BEHIND THE COLD FRONT WILL LIKELY LEAD TO STRATUS FORMATION...ESPECIALLY NORTH CLOSER TO THE LAKES. A FEW SPOTTY SHOWERS ARE EXPECTED NORTH WEDNESDAY INTO THURSDAY IN THE COOL NORTHWEST FLOW ACROSS THE LAKES. WITH THE COOLER AIR MASS SINKING IN...AND EXPECTED STRATUS...HAVE TRIMMED MAXES BACK. THE CLOUD COVER COULD LEAD TO A FAIRLY LARGE TEMP GRADIENT THURSDAY...WITH READINGS IN THE LOW 60S NORTH...TO THE MID TO UPPER 70S SOUTH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... HIGH PRESSURE WITH NEAR SEASONAL TEMPS WILL DOMINATE INTO FRIDAY. AS HIGH MOVES EAST STORM SYSTEM IN THE NORTHERN PLAINS WILL PUSH A WARM FRONT ACROSS REGION SATURDAY WITH WARMING TEMPERATURES ALONG WITH INCREASING MOISTURE AND SHOWER CHANCES. COLD FRONT WILL MOVE ACROSS REGION SUNDAY WITH MILD CONDITIONS AND SHOWERS. CLOSE TO HPC PROGS THROUGH PERIOD. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... MOSTLY CLEAR SKIES WILL PREVAIL THROUGH THIS AFTN AS RIDGING CROSSES THE AREA. MAINLY LIGHT WINDS EARLY THIS MORNING WILL INCREASE TO S/SW AT 10-14KT WITH GUSTS TO 25KT THIS AFTN. CLOUDS WILL INCREASE BY EARLY THIS EVENING AS A COLD FRONT APPROACHES. THINK A 2-4 HOUR PERIOD OF SHWRS WILL OCCUR ALONG THE BOUNDARY...THUS HAVE INCLUDED VFR SHWRS FROM 01-04Z AT ZZV...03-07Z AT HLG/FKL/AGC/PIT/BVI...AND 06-09Z FOR LBE/MGW/DUJ. ANY RESTRICTIONS WILL BE VERY SHORT LIVED AND NOT INCLUDED IN THE TERMINALS. LINGERING STRATOCUMULUS WILL PREVAIL WEDNESDAY IN THE WAKE OF THE COLD FRONT...WITH AN ISOLATED SHWR POSSIBLE NORTH OF PIT...WITH SOME MVFR RESTRICTIONS POSSIBLE. VFR CONDITIONS AREA WIDE ARE EXPECTED THURSDAY/FRIDAY UNDER HIGH PRESSURE...WITH A CHANCE OF SHWRS AND RESTRICTIONS RETURNING FOR SATURDAY AS THE NEXT FRONTAL SYSTEM IS PROGGED TO AFFECT THE AREA. && .FIRE WEATHER... WITH RECENT RELATIVELY DRY WEATHER...10 HOUR FUEL MOISTURE HAS DROPPED BELOW 10 PERCENT ACROSS MUCH OF THE UPPER OHIO VALLEY. A DRY SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT TODAY WILL ALLOW FOR RELATIVE HUMIDITY VALUES TO DROP INTO THE 30S THIS AFTERNOON. IN ADDITION...A TIGHT PRESSURE GRADIENT WILL INCREASE WINDS TO 15 MPH WITH GUSTS TO 25 MPH. SPC HAS HIGHLIGHTED THE AREA WITH A SEE TEXT PRODUCT...WITH THE COMBINATION OF DRY WEATHER AND GUSTY WINDS LEADING TO AN ENHANCED FIRE WEATHER THREAT. AT THE MOMENT...FORECAST WIND AND MIN RH PARAMETERS ARE MARGINAL. DO NOT ANTICIPATE FIRE WEATHER HEADLINES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 000 FXUS61 KPHI 071612 CCA AFDPHI AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1212 PM EDT TUE SEP 7 2010 .SYNOPSIS... A BRIEF WARM UP ASSOCIATED WITH BERMUDA HIGH PRESSURE WILL END SEVERAL HOURS AFTER WEDNESDAYS COLD FRONTAL PASSAGE. A COOLER THAN NORMAL AIR MASS WILL ARRIVE EARLY THURSDAY AND LAST INTO THE WEEKEND AS LARGE HIGH PRESSURE IN CENTRAL CANADA HEADS FOR THE MID ATLANTIC COAST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO SIGNIFICANT CHANGES TO THE GOING FORECAST THIS MORNING. MOST CHANGES ARE TO ACCOUNT FOR TRENDS IN CLOUDS...TEMPERATURES AND DEW POINTS. THE SURFACE HIGH HAS MOVED OFFSHORE...AND THE RETURN FLOW HAS ALLOWED DEW POINTS TO RISE INTO THE LOWER TO MID 60S THIS MORNING. WOULD EXPECT MIXING TO DROP THESE DEW POINT VALUES 5 TO 10 DEGREES THIS AFTERNOON. 1200 UTC SOUNDINGS SHOWED MARGINAL INSTABILITY WITH THE HIGHER DEW POINTS...BUT THE SOUNDINGS OVERALL WERE STILL FAIRLY DRY. ANY INSTABILITY PROBABLY GETS ERASED WITH WARMING AND MIXING. CUMULUS DEVELOPMENT SHOULD BE LIMITED IN VERTICAL THIS AFTERNOON AS MID LEVEL HEIGHTS ARE NOW FAIRLY HIGH...WITH CAPPING IN PLACE. WILL SEE A BATCH OF CIRRUS MOVE ACROSS THE FORECAST AREA THIS AFTERNOON FROM WESTERN PENNSYLVANIA...BUT IT LOOKS THIN ENOUGH FOR MOSTLY SUNNY. THE BEST SURFACE GRADIENT AROUND THE HIGH OFF THE MID ATLANTIC COAST AND THE COLD FRONT OVER THE GREAT LAKES SHOULD ARRIVE OR MIX DOWN ACROSS WESTERN AREAS LATE THIS MORNING...AND ELSEWHERE THIS AFTERNOON. MAY HAVE TO ADD A GUST TO 20-25 MPH TO SOME AREAS FOR THE AFTERNOON...BASED ON THE WINDS AT THE TOP OF THE INVERSION THIS MORNING. 1200 UTC SOUNDINGS SHOW HIGHS IN THE MID 80S TO LOWER 90S FROM NORTH TO SOUTH. THIS IS IN LINE WITH CURRENT FORECAST HIGHS AND NOT MUCH CHANGE WAS MADE HERE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...A FAIR START. THEN A 3 HOUR WINDOW ARRIVES FROM W TO E ACROSS E PA... W NJ AND MD N DEL BETWEEN 06Z AND 12Z IN WHICH A 1 HR WIDE BAND OF SCT SHOWERS AND EMBEDDED TSTMS WILL TRAVERSE THE AREA. BEST CHC FOR A GUSTY TSTM IS THE POCONOS WHERE THE COMBO OF MODELED MLCAPE AT 06Z VCNTY AOO AND LARGE TT NEAR 55 AND KI NR 36 SWEEPS THAT REGION. POPS ARE BLENDED 21Z/00Z RESPECTIVELY SREF/NAM AND GFS GUIDANCE WITH A LEAN TOWARD TO THE GFS MOS GUIDANCE. DID NOT THE DRY UK AND GGEM BUT I PREFER NCEP MODELS FOR CONVECTION. WED...RAPID CLEARING BY FORENOON AFTER WHATEVER CONVECTION SWEEPS EWD THRU NJ/DEL IN THE 12Z-14Z TIME FRAME. THEN HOT FOR SEVERAL HOURS AND RELIED ON THE 00Z/7 UK/NAM 2M TEMPS AGAIN FCSTG WELL ABOVE MOS GUIDANCE. THIS ALSO SETS THE STAGE FOR GUSTY W WINDS TO OF 27 TO 33 KNOTS WITH LARGE 850/SFC LAPSE RATES IN THE AFTN ENHANCING MOMENTUM TRANSFER AND DEWPOINTS TUMBLING INTO THE 40S. BELIEVE WED AFTN IS AN IDEAL RED FLAG SITN FOR WRI-PHL-NEAR LNS CORRIDOR. WED NIGHT-FRIDAY FCST IS BASICALLY A BLEND OF NAM/GFS MOS TEMPS WITH GUSTY DIURNAL WINDS AND CU FIELDS EACH AFTN ALONG WITH A DECENT CHANCE OF SPRINKLES OR SCT SHOWERS THU AFTN/EVE N NJ AND POCONOS. AT NIGHT...CLEARING AND RATHER COOL IN THE COUNTRYSIDE WITH DECOUPLING. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THE LONGER RANGE PERIOD OF THE FORECAST APPEARS TO HAVE SEVERAL MODERATE AMPLITUDE BUT PROGRESSIVE UPPER AIR FEATURES AFFECTING OUR AREA. GOING ALONG WITH HPC...THE MOST RECENT GFS MODELS WAS USED FOR MUCH OF THE EXTENDED FCST. AT THE BEGINNING OF THE PERIOD...AN OFFSHORE EAST COAST TROUGH AND UPPER RIDGE OVER THE MISSISSIPPI VALLEY WILL FAVOR A DRY PATTERN ACROSS THE REGION. THE RIDGE AND ITS ASSOCIATED SFC HIGH ONLY SLOWLY MOVE EASTWARD...THUS THE DRY WEATHER WILL CONTINUE PROBABLY THROUGH SATURDAY NIGHT. A WEAKENING SHORT WAVE MOVING ACROSS THE GREAT LAKES AND NORTHEAST WILL SEND A FRONT THROUGH THE AREA EARLY SUNDAY...SO CHC OR SLGT CHC POPS WERE KEPT IN THE GRIDS FOR THESE PERIODS. THE FEATURE DOES NOT LOOK TO BE A SIGNIFICANT PRECIPITATION MAKES...ESPECIALLY CONSIDERING HOW QUICKLY IT WILL MOVE THROUGH. THE UPPER FLOW BECOMES MORE WESTERLY BY EARLY NEXT WEEK AND A RIDGE WILL BE BUILDING OUT TO THE WEST AGAIN...SO ANOTHER PERIOD OF FAIR WEATHER WILL ARRIVE EARLY NEXT WEEK. THE 12Z/06 GFS IS AT ODDS WHEN COMPARED TO THE 00Z/06 ECMWF. I HAVE SIDED BACK WITH THE OLDER ECMWF FOR MONDAY AND INDICATED A DRY FCST SINCE THE LINGERING MOISTURE WITH THE PROGRESSIVE FLOW LOOKS SHOWN BY THE GFS LOOKS STRANGE. TEMPERATURES DURING THE PERIOD WILL NOT SHOW TOO MANY EXTREMES. IT WILL LIKELY BE NORMAL OR A LITTLE BELOW NORMAL FRIDAY AND SATURDAY AND THEN A LITTLE ABOVE NORMAL SUNDAY AND MONDAY. NORMAL HIGHS FOR THIS PERIOD ARE IN THE MID TO UPPER 70S WITH NORMAL LOWS IN THE MID TO UPPER 50S. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. EXCELLENT FLYING WX WILL CONTINUE THROUGH THE TAF PD. VFR IS EXPECTED THROUGH MOST, IF NOT ALL OF THE PD. AN AREA OF HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY EWD TODAY. AS IT DOES, A CDFNT WILL BEGIN TO APPROACH FROM THE W AND MOVE THROUGH THE TAF SITED GENLY FROM W TO E OVERNIGHT TONIGHT AND INTO WEDNESDAY MORNING. THERE WILL MAINLY BE SOME HIGH CI TODAY AND TONIGHT. WINDS WILL BE GENLY FROM THE SW INCREASING DURG THE DAY AND BECOMING GUSTY. WIND SPEEDS ARE GENLY EXPECTED IN THE 10 TO 15 KT RANGE WITH GUSTS TO AROUND 20 KT. WINDS WILL DECREASE TO 10 KT OR LESS AFTER SUNSET. WHEN THE CDFNT CROSSES THE AREA, THERE COULD BE A FEW SHOWERS OR EVEN TSRA, BUT PRECIP CHCS REMAIN VERY LOW. IF THERE ARE ANY SHWRS/TSTMS, THERE COULD BE SOME LOCAL MVFR CONDS. OUTLOOK... HIGH PRESSURE BUILDS BACK IN BEHIND THE FRONT AND VFR CONDS CONTINUE TO RULE. WINDS WILL BECOME W AND THEN NW AFTER FROPA. FAIR WX IS THEN EXPECTED THROUGH THE END OF THE WEEK. && .MARINE... HIGH PRESSURE WILL MOVE SLOWLY EWD TODAY AS A CDFNT BEGINS TO APPROACH FROM THE W. AS THE FRONT GETS CLOSER, SWLY WINDS AND SEAS WILL INCREASE. WAVEWATCH DATA INDICATES SOME POTENTIAL FOR SCA SEAS AND PSBLY WINDS OVER THE N TONIGHT INTO WEDNESDAY, BUT CONFIDENCE IS LOW. WIND SPEEDS APPEAR TO BE MARGINAL AS WELL. THEREFORE, WILL NOT ISSUE ANY MARINE FLAGS ATTM, BUT THEY MAY BE NEEDED AT SOME POINT. THE CDFNT WILL CROSS THE MARINE AREA ON WEDNESDAY AND WINDS WILL SHIFT TO THE W AND THEN NW AS HIGH PRESSURE BUILDS BACK OVER THE AREA BRINGING COOLER AND DRIER AIR. DESPITE THE COOLER AMS, THE WINDS DO APPEAR TO REMAIN BELOW SCA CRITERIA BEHIND THE FRONT AS WELL. && .FIRE WEATHER... IT APPEARS AS THOUGH THE MINIMUM RELATIVE HUMIDITY WILL BE THE LIMITING FACTOR AGAINST THE ISSUANCE OF A RED FLAG WARNING FOR THIS AFTERNOON. 1200 UTC OBSERVED SOUNDINGS AND 0600 UTC MODEL SOUNDINGS SUGGEST THAT MIXING WILL OCCUR FROM 857-900 MB...AND THIS WOULD DROP DEW POINT INTO THE MID 50S (FROM THE LOWER TO MID 60S THEY ARE NOW). DROPPING THE DEW POINTS 10 DEGREES BRINGS MINIMUM RELATIVE HUMIDITY TO ABOUT 31 OR 32 PERCENT FOR THE AFTERNOON. STILL EXPECT TO SEE WINDS GUST TO 20-25 MPH FOR A TIME DURING THE MID TO LATE AFTERNOON...WHICH WOULD BE ABOUT THE TIME OF THE LOWEST DEW POINTS. THE COMBINATION FALLS SHORT OF RED FLAG CRITERIA. WILL INSTEAD ISSUE A SPECIAL WEATHER STATEMENT FOR ENHANCED FIRE DANGER FOR THIS AFTERNOON. WILL CONTINUE TO MONITOR CONDITIONS...AND A SHORT FUSED RED FLAG WARNING IS STILL POSSIBLE FOR THIS AFTERNOON. WILL MAKE A DECISION CONCERNING THE FIRE WEATHER WATCH THIS AFTERNOON. AGAIN...MINIMUM RELATIVE HUMIDITY VALUES MAY END UP BEING THE LIMITING FACTOR. FOR WED AFTERNOON...2PM-7 PM TIME FRAME. 00Z/NAM SUGGESTS THE FIRE DANGER UNFOLDS RAPIDLY AROUND 2-3 PM AS DEWPOINTS PLUMMET INTO THE MID AND UPPER 40S WITH RAPIDLY DESTABILIZING LAPSE RATES AND DECENT SHOT OF DRY ADVECTION CONTRIBUTING TO MOMENTUM TRANSFER. MOST WIND GUSTS 25-30 MPH BUT ISOLATED GUSTS TO 38 MPH EXPECTED. BUFKIT SIGNAL UPPER LIMIT IS NEAR 40 KNOTS. WILL DEPEND ON HOW HOT IT GETS. && .CLIMATE... PORTIONS OF THIS CLIMATE SECTION WILL BE DELETED BY THIS AFTERNOON. MARCH THROUGH AUGUST 2010 /6 MONTH PERIOD PERIOD/ OF RECORD WARMTH. AVG TEMPS DEPARTURE PREVIOUS RECORD YEAR ACY PLUS 2.3 1991 PHL PLUS 1.2 1991 ILG PLUS 1.0 1973 ABE PLUS 0.4 1991 SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE. IT LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! CONSECUTIVE DAYS WITHOUT RAIN /TRACE OR LESS/ THROUGH TUESDAY 9/7: ABE 15 PHL 15 RDG 15 TTN 14 ILG 14 MPO 14 GED AND ACY HAD OUTER EDGE OF "EARL" SHOWERS ON THE 3RD. IF IT DOESNT RAIN /MEASURE/ WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...I.E. 17-18 CONSECUTIVE DAYS. OFFICE CLIMATE TOOLS INDICATE 17-18 CONSECUTIVE DAYS TRACE OR ZERO IS FAR SHORT OF ANY RECORD. YEARLY 90 PLUS THROUGH LABOR DAY 9/6... PHL 51 TWO SHORT OF EQUALING THE 1991 RER. RANK #2. POR TO 1873. ACY 43 TIES 1983 FOR THE MOST. TODAY 9/7 LIKELY EXCEEDS! POR TO 1906. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR PAZ060-061-067>071. NJ...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR NJZ009-010-012>027. DE...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR DEZ001-002. MD...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR MDZ008-012-015. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER...HAYES/DRAG CLIMATE...DRAG US Dept of Commerce National Oceanic and Atmospheric Administration National Weather Service 1325 East West Highway Silver Spring, MD 20910 Page Author: NWS Internet Services Team Disclaimer Information Quality Credits Glossary Privacy Policy Freedom of Information Act (FOIA) About Us Career Opportunities
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