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Forecast Discussion - NOAA's National Weather Service Latest: AFDPHI| [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 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 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 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 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 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 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 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 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 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 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 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 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 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 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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