eastcoastweather

Forecast Discussion - NOAA's National Weather Service Latest: AFDPHI| [top] 000 FXUS61 KPHI 061312 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 912 AM EDT MON SEP 6 2010 .SYNOPSIS... GENERALLY DRY WEATHER CONTINUES INTO THE START OF THE WEEKEND. COOL HIGH PRESSURE OVERHEAD WILL MERGE WITH THE BERMUDA HIGH ON TUESDAY PERMITTING A BRIEF RETURN OF VERY WARM AIR. WEDNESDAYS COLD FRONTAL PASSAGE MAY BE ACCOMPANIED BY A SHOWER OR SPRINKLE. LARGE AND COOL HIGH PRESSURE IN CENTRAL CANADA ARRIVES IN THE MID ATLANTIC STATES BY THIS WEEKEND WITH SEVERAL DAYS OF NEAR OR BELOW NORMAL TEMPERATURES BEGINNING ON THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATCHING LOW LEVEL MOISTURE (THE SOURCE FOR WHICH APPEARS TO BE THE CHESAPEAKE) RISING AND BECOME TRAPPED UNDER THE INVERSION SEEN AT ABOUT 5000 FEET ON THE 1200 UTC KIAD SOUNDING. THE AREA IS EXPANDING INTO NEARBY SOUTHEAST PENNSYLVANIA AND NORTHEAST MARYLAND. THE CLOUD COVER WAS INCREASED THIS MORNING TO ACCOUNT FOR THE MOISTURE. WHILE IT WOULD APPEAR AS THOUGH THIS MOISTURE SHOULD MIX OUT WITH DRIER AIR IN THE BOUNDARY LAYER. WILL CONTINUE TO WATCH THE TREND AND UPDATE IF THE PLUME OF MOISTURE BECOMES LARGER. ALSO INCREASED THE CLOUD COVER ALONG THE EASTERN SHORE AS LOW LEVEL MOISTURE IS TRAPPED HERE AS WELL. DEW POINTS ARE A FEW DEGREES HIGHER (AGAIN APPARENTLY DUE TO THE PROXIMITY TO THE WARM BAY)... AND THIS MAY TAKE LONGER TO MIX OUT. THIS WAS INDICATED IN THE SKY COVER...AND WILL WATCH THE TRENDS HERE AS WELL. OTHERWISE...THE NEXT BAND OF SIGNIFICANT CLOUD COVER LIES ACROSS WESTERN PENNSYLVANIA AHEAD OF A SHORT WAVE. EXTRAPOLATION BRINGS THESE MID LEVEL CLOUDS TO NORTHER AREAS AFTER 1700 UTC. THIS IS BEING FAIRLY WELL MODELED BY THE 0600 UTC NAM...AND THE MOISTURE FIELD WAS USED AS A GUIDE FOR CLOUDS ACROSS THE NORTH THIS AFTERNOON. 1200 UTC SOUNDINGS SHOW THAT CONVECTIVE TEMPERATURES ARE GENERALLY WITHIN REACH...AND SCATTERED CUMULUS SHOULD DEVELOP BY LATE MORNING IN MOST PLACES. SOUNDINGS INDICATE HIGHS IN THE UPPER 70S TO LOWER 80S. THIS IS IN LINE WITH THE CURRENT FORECAST AND MOS NUMBERS. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...FAIR. PATCHY FOG POSSIBLE LATE. SHOULD BE A BIT MORE EXTENSIVE THAN THE ISOLATED REPORTS RCD AS OF 440 AM. TUESDAY...SUNNY AND WARMER! MORE HUMID. SW FLOW ON THE BACK SIDE OF BERMUDA HIGH. MAY REACH 90F IN A FAIR CHUNK OF S NJ...DEL E MAD AND AROUND PHILADELPHIA. FCST IS CONSERVATIVE BECAUSE OF NCEP MOS GUIDANCE. SW WIND GUSTS 15-20 KTS IN THE AFTERNOON. TUESDAY NIGHT...POSSIBLE CLOUD BAND AND SCATTERED DECAYING SHOWERS OR SPRINKLES ARRIVING IN EASTERN PA AND NW NJ TOWARD DAWN! OTRW FAIR AND MILD. WEDNESDAY...MODELED WEAKENING INSTABILITY BURST APPARENTLY FRITTERS AS IT CROSSES OUR CWA WED MORNING ALLOWING A BETTER CHANCE TO HEAT TO 90F WITHOUT INTERRUPTION OF PERSISTENT CLOUD COVER OR ANY SHOWERS. LOW PROBABILITY OF RAIN. IN FUTURE FCST TEMPS ON WEDNESDAY MAY NEED TO BE RAISED A DEGREE OR 2 IF IT BECOMES MOSTLY SUNNY BY NOON. THEN IT BECOMES INTERESTING WITH CAA ALOFT AND GUSTY WESTERLY WINDS TRANSPORTING MUCH DRIER AIR INTO THE AREA DURING THE AFTERNOON. THURSDAY...SHOULD ALSO SEE DRY GUSTY NW WINDS TO 20 KNOTS AND LOW AFTERNOON RH WITH THE TROUGH ALOFT IN NEW ENGLAND. CALENDAR AVG TEMPERATURES PROBABLY BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. UNCERTAINTY FOR THE UPCOMING WEEKEND REGARDING TIMING OF THE UPPER MIDWEST SHORT WAVE AND ASSOCIATED SHOWER/WAA THREAT. MERGED 4PM SUNDAY OFFICIAL FCST TEMPS WITH NEW 00Z/6 GFS/ECMWF GUIDANCE TO RUN A BIT COOLER INTO SATURDAY. THE 00Z/6 46 MEMBER NAEFS IS FAVORING A CHANCE OF SHOWERS SUNDAY INTO MONDAY. THEREFORE...LOW CONFIDENCE ON TIMING OF A MORE SIGNIFICANT SHOWER THREAT HERE THIS WEEKEND. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A QUIET FEW DAYS ACRS THE AREA AS HIGH PRESSURE REMAINS IN CONTROL AND VFR CONDS PREVAIL. A S TO SW FLOW WILL OCCUR TODAY WITH SPEEDS GENLY 10 KTS OR LESS. WINDS WILL BECOME LIGHT OVERNIGHT, GENLY FROM THE S OR SW AND BECOME A BIT MORE SWLY ON TUESDAY, WITH SPEEDS GENLY IN THE 10 TO 15 KT RANGE. THERE WILL BE FEW IF ANY CLOUDS. WITH THE LIGHT FLOW, BIT OF A SEABREEZE MAY DEVELOP AT KACY THIS AFTN. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE MOST OF THIS WEEK. AS HIGH SLOWLY MOVES OFF THE COAST. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. IT IS PSBL THAT THERE IS A BRIEF PD OF MVFR CIGS OR VSBYS IF THERE ARE ANY DECENT SHOWERS. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE BUILDS BACK IN. && .MARINE... A TRANQUIL FEW DAYS ARE IN STORE FOR THE AREA WATERS AS HIGH PRESSURE REMAINS IN CONTROL. LIGHT WINDS TODAY, GENLY 10 KT OR LESS WILL ALLOW FOR THE POSSIBILITY OF A SEA/BAY BREEZE AND S TO SW WINDS COULD BECOME SELY OR ELY. A RETURN TO MORE SWLY FLOW IS ANTICIPATED ON TUESDAY. NO MARINE FLAGS ARE ANTICIPATED MONDAY OR TUESDAY. A CDFNT WILL APPROACH FROM THE WEST AND CROSS THE WATERS ON WEDNESDAY. LATEST GUIDANCE INDICATES THAT SEAS COULD REACH SCA CRITERIA, ESPECIALLY OVER THE NRN WATERS. HOWEVER, WITH A WARM AMS IN PLACE, THE GUIDANCE MAY BE OVERDONE. NWLY FLOW WILL MOVE IN BEHIND THE DEPARTING FRONT. && .FIRE WEATHER... LOW PROBABILITY OF RED FLAG CONDITIONS IS OUTLOOKED IN THE 2 PM TO 8 PM TIME FRAME LATE WEDNESDAY AS GUSTY DRY CAA WINDS FOLLOW THE WEDNESDAY LATE MORNING CFP. NO ACTION ATTM DUE TO NORMAL UNCERTAINTIES WITH RH AND GUSTINESS MEETING CRITERIA AS WELL AS CONSULTING WITH FIRE OFFICIALS. HOWEVER... WE SHOULD HAVE NO PROBLEM MAINTAINING VERY DRY 10 HOUR FUELS. IT HASNT RAINED HERE BASICALLY IN THE THE 22ND-24TH WHICH IS 12 DAYS THROUGH YESTERDAY AND ADD A COUPLE OF DAYS /TODAY AND TUESDAY/ WHICH WILL MAKE IT 2 WEEKS OF DRY WEATHER! ANY SCATTERED SHOWERS WEDNESDAY MORNING WILL PROBABLY BE NEGLIGIBLE AND AND A NON FACTOR IN LIMITING INCREASED RATE OF SPREAD POTENTIAL. AS FYI...GUSTS TO 20 KNOTS TUE AFTN BUT RH SHOULD REMAIN JUST ABOVE THRESHOLD. && .CLIMATE... JUST IN CASE...PRESUME ALL ARE AWARE OF THE 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 THE 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: THROUGH TUESDAY IT WILL BE GENERALLY 2 WEEKS WITHOUT RAIN HERE IN OUR CWA. IF IT DOESNT RAIN WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...OR 17 CONSECUTIVE DAYS. HOWEVER..FROM WHAT I CAN TELL IN OUR OFFICE CLIMATE TOOLS...17 DAYS IS FAR SHORT OF ANY RECORD FOR CONSECUTIVE DAYS WITH NO RAIN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM.../ AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER...DRAG CLIMATE...DRAG 000 FXUS61 KPHI 060859 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 459 AM EDT MON SEP 6 2010 .SYNOPSIS... GENERALLY DRY WEATHER CONTINUES INTO THE START OF THE WEEKEND. COOL HIGH PRESSURE OVERHEAD WILL MERGE WITH THE BERMUDA HIGH ON TUESDAY PERMITTING A BRIEF RETURN OF VERY WARM AIR. WEDNESDAYS COLD FRONTAL PASSAGE MAY BE ACCOMPANIED BY A SHOWER OR SPRINKLE. LARGE AND COOL HIGH PRESSURE IN CENTRAL CANADA ARRIVES IN THE MID ATLANTIC STATES BY THIS WEEKEND WITH SEVERAL DAYS OF NEAR OR BELOW NORMAL TEMPERATURES BEGINNING ON THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BEFORE 7 AM...ISO PATCHES SHALLOW 1MI FOG SO FAR ONLY MMU. PATCHY CU SHOULD FORM LATE THIS MORNING AND THERE MAY BE A PERIOD OF MIDDLE DECK LATE THIS AFTERNOON BUT ESSENTIALLY A MOSTLY SUNNY DAY. MAX TEMPS MOST OF THE CWA SHOULD BE 80-85...A BIT COOLER POCONOS AND NW NJ. SEA BREEZES THIS AFTN ALONG THE COAST. 4AM FCST SFC TDS MAY BE A FEW DEGREES TOO LOW ALONG THE COAST LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...FAIR. PATCHY FOG POSSIBLE LATE. SHOULD BE A BIT MORE EXTENSIVE THAN THE ISOLATED REPORTS RCD AS OF 440 AM. TUESDAY...SUNNY AND WARMER! MORE HUMID. SW FLOW ON THE BACK SIDE OF BERMUDA HIGH. MAY REACH 90F IN A FAIR CHUNK OF S NJ...DEL E MAD AND AROUND PHILADELPHIA. FCST IS CONSERVATIVE BECAUSE OF NCEP MOS GUIDANCE. SW WIND GUSTS 15-20 KTS IN THE AFTERNOON. TUESDAY NIGHT...POSSIBLE CLOUD BAND AND SCATTERED DECAYING SHOWERS OR SPRINKLES ARRIVING IN EASTERN PA AND NW NJ TOWARD DAWN! OTRW FAIR AND MILD. WEDNESDAY...MODELED WEAKENING INSTABILITY BURST APPARENTLY FRITTERS AS IT CROSSES OUR CWA WED MORNING ALLOWING A BETTER CHANCE TO HEAT TO 90F WITHOUT INTERRUPTION OF PERSISTENT CLOUD COVER OR ANY SHOWERS. LOW PROBABILITY OF RAIN. IN FUTURE FCST TEMPS ON WEDNESDAY MAY NEED TO BE RAISED A DEGREE OR 2 IF IT BECOMES MOSTLY SUNNY BY NOON. THEN IT BECOMES INTERESTING WITH CAA ALOFT AND GUSTY WESTERLY WINDS TRANSPORTING MUCH DRIER AIR INTO THE AREA DURING THE AFTERNOON. THURSDAY...SHOULD ALSO SEE DRY GUSTY NW WINDS TO 20 KNOTS AND LOW AFTERNOON RH WITH THE TROUGH ALOFT IN NEW ENGLAND. CALENDAR AVG TEMPERATURES PROBABLY BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. UNCERTAINTY FOR THE UPCOMING WEEKEND REGARDING TIMING OF THE UPPER MIDWEST SHORT WAVE AND ASSOCIATED SHOWER/WAA THREAT. MERGED 4PM SUNDAY OFFICIAL FCST TEMPS WITH NEW 00Z/6 GFS/ECMWF GUIDANCE TO RUN A BIT COOLER INTO SATURDAY. THE 00Z/6 46 MEMBER NAEFS IS FAVORING A CHANCE OF SHOWERS SUNDAY INTO MONDAY. THEREFORE...LOW CONFIDENCE ON TIMING OF A MORE SIGNIFICANT SHOWER THREAT HERE THIS WEEKEND. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A QUIET FEW DAYS ACRS THE AREA AS HIGH PRESSURE REMAINS IN CONTROL AND VFR CONDS PREVAIL. A S TO SW FLOW WILL OCCUR TODAY WITH SPEEDS GENLY 10 KTS OR LESS. WINDS WILL BECOME LIGHT OVERNIGHT, GENLY FROM THE S OR SW AND BECOME A BIT MORE SWLY ON TUESDAY, WITH SPEEDS GENLY IN THE 10 TO 15 KT RANGE. THERE WILL BE FEW IF ANY CLOUDS. WITH THE LIGHT FLOW, BIT OF A SEABREEZE MAY DEVELOP AT KACY THIS AFTN. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE MOST OF THIS WEEK. AS HIGH SLOWLY MOVES OFF THE COAST. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. IT IS PSBL THAT THERE IS A BRIEF PD OF MVFR CIGS OR VSBYS IF THERE ARE ANY DECENT SHOWERS. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE BUILDS BACK IN. && .MARINE... A TRANQUIL FEW DAYS ARE IN STORE FOR THE AREA WATERS AS HIGH PRESSURE REMAINS IN CONTROL. LIGHT WINDS TODAY, GENLY 10 KT OR LESS WILL ALLOW FOR THE POSSIBILITY OF A SEA/BAY BREEZE AND S TO SW WINDS COULD BECOME SELY OR ELY. A RETURN TO MORE SWLY FLOW IS ANTICIPATED ON TUESDAY. NO MARINE FLAGS ARE ANTICIPATED MONDAY OR TUESDAY. A CDFNT WILL APPROACH FROM THE WEST AND CROSS THE WATERS ON WEDNESDAY. LATEST GUIDANCE INDICATES THAT SEAS COULD REACH SCA CRITERIA, ESPECIALLY OVER THE NRN WATERS. HOWEVER, WITH A WARM AMS IN PLACE, THE GUIDANCE MAY BE OVERDONE. NWLY FLOW WILL MOVE IN BEHIND THE DEPARTING FRONT. && .FIRE WEATHER... LOW PROBABILITY OF RED FLAG CONDITIONS IS OUTLOOKED IN THE 2 PM TO 8 PM TIME FRAME LATE WEDNESDAY AS GUSTY DRY CAA WINDS FOLLOW THE WEDNESDAY LATE MORNING CFP. NO ACTION ATTM DUE TO NORMAL UNCERTAINTIES WITH RH AND GUSTINESS MEETING CRITERIA AS WELL AS CONSULTING WITH FIRE OFFICIALS. HOWEVER... WE SHOULD HAVE NO PROBLEM MAINTAINING VERY DRY 10 HOUR FUELS. IT HASNT RAINED HERE BASICALLY IN THE THE 22ND-24TH WHICH IS 12 DAYS THROUGH YESTERDAY AND ADD A COUPLE OF DAYS /TODAY AND TUESDAY/ WHICH WILL MAKE IT 2 WEEKS OF DRY WEATHER! ANY SCATTERED SHOWERS WEDNESDAY MORNING WILL PROBABLY BE NEGLIGIBLE AND AND A NON FACTOR IN LIMITING INCREASED RATE OF SPREAD POTENTIAL. AS FYI...GUSTS TO 20 KNOTS TUE AFTN BUT RH SHOULD REMAIN JUST ABOVE THRESHOLD. && .CLIMATE... JUST IN CASE...PRESUME ALL ARE AWARE OF THE 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 THE 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: THROUGH TUESDAY IT WILL BE GENERALLY 2 WEEKS WITHOUT RAIN HERE IN OUR CWA. IF IT DOESNT RAIN WEDNESDAY... WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST THIS FRIDAY...OR 17 CONSECUTIVE DAYS. HOWEVER..FROM WHAT I CAN TELL IN OUR OFFICE CLIMATE TOOLS...17 DAYS IS FAR SHORT OF ANY RECORD FOR CONSECUTIVE DAYS WITH NO RAIN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM.../ AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER... CLIMATE... 000 FXUS61 KPHI 060820 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 420 AM EDT MON SEP 6 2010 .SYNOPSIS... GENERALLY DRY WEATHER CONTINUES INTO THE START OF THE WEEKEND. COOL HIGH PRESSURE OVERHEAD WILL MERGE WITH THE BERMUDA HIGH ON TUESDAY PERMITTING A BRIEF RETURN OF VERY WARM AIR. WEDNESDAYS COLD FRONTAL PASSAGE MAY BE ACCOMPANIED BY A SHOWER OR SPRINKLE. LARGE AND COOL HIGH PRESSURE IN CENTRAL CANADA ARRIVES IN THE MID ATLANTIC STATES BY THIS WEEKEND WITH SEVERAL DAYS OF NEAR OR BELOW NORMAL TEMPERATURES BEGINNING ON THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PATCHY CU SHOULD FORM LATE THIS MORNING AND THERE MAY BE A PERIOD OF MIDDLE DECK LATE THIS AFTERNOON BUT ESSENTIALLY A MOSTLY SUNNY DAY. MAX TEMPS MOST OF THE CWA SHOULD BE 80-85...A BIT COOLER POCONOS AND NW NJ. SEA BREEZES THIS AFTN ALONG THE COAST. SFC TDS MAY BE A FEW DEGREES TOO LOW ALONG THE COAST LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...FAIR. PATCHY FOG POSSIBLE LATE. TUESDAY...SUNNY AND WARMER! MORE HUMID. SW FLOW ON THE BACK SIDE OF BERMUDA HIGH. MAY REACH 90F IN A FAIR CHUNK OF S NJ...DEL E MAD AND AROUND PHILADELPHIA. FCST IS CONSERVATIVE BECAUSE OF NCEP MOS GUIDANCE. TUESDAY NIGHT...POSSIBLE CLOUD BAND AND SCATTERED DECAYING SHOWERS OR SPRINKLES ARRIVING IN EASTERN PA AND NW NJ TOWARD DAWN! OTRW FAIR AND MILD. WEDNESDAY...WEAKENING INSTABILITY BURST APPARENTLY FRITTERS AS IT CROSSES OUR CWA WED MORNING ALLOWING A BETTER CHANCE TO HEAT TO 90F WITHOUT INTERRUPTION OF PERSISTENT CLOUD COVER OR ANY SHOWERS. LOW PROB OF RAIN. THROUGH TUESDAY...IT WILL BE GENERALLY 2 WEEKS WITHOUT RAIN HERE IN OUR CWA. IF IT DOESNT RAIN WEDNESDAY...WE`RE LIKELY TO EXTEND THE DRY SPELL THROUGH AT LEAST FRIDAY...OR 17 CONSECUTIVE DAYS. TEMPS ON WEDNESDAY MAY NEED TO BE RAISED A DEGREE OR 2 IF IT BECOMES MOSTLY SUNNY BY NOON. THEN IT BECOMES INTERESTING WITH CAA ALOFT AND GUSTY WESTERLY WINDS TRANSPORTING MUCH DRIER AIR INTO THE AREA DURING THE AFTERNOON. THURSDAY...SHOULD ALSO SEE DRY GUSTY NW WINDS AND LOW AFTERNOON RH WITH THE TROUGH ALOFT IN NEW ENGLAND. CALENDAR AVG TEMPERATURES PROBABLY BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. UNCERTAINTY FOR THE UPCOMING WEEKEND REGARDING TIMING OF THE UPPER MIDWEST SHORT WAVE AND ASSOCIATED SHOWER/WAA THREAT. MERGED 4PM SUNDAY OFFICIAL FCST TEMPS WITH NEW 00Z/6 GFS/ECMWF GUIDANCE TO RUN A BIT COOLER INTO SATURDAY. THE 00Z/6 46 MEMBER NAEFS IS FAVORING A CHANCE OF SHOWERS SUNDAY INTO MONDAY. ATTM LOW CONFIDENCE ON TIMING OF A MORE LEGIT SHOWER THREAT THIS WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A QUIET FEW DAYS ACRS THE AREA AS HIGH PRESSURE REMAINS IN CONTROL AND VFR CONDS PREVAIL. A S TO SW FLOW WILL OCCUR TODAY WITH SPEEDS GENLY 10 KTS OR LESS. WINDS WILL BECOME LIGHT OVERNIGHT, GENLY FROM THE S OR SW AND BECOME A BIT MORE SWLY ON TUESDAY, WITH SPEEDS GENLY IN THE 10 TO 15 KT RANGE. THERE WILL BE FEW IF ANY CLOUDS. WITH THE LIGHT FLOW, BIT OF A SEABREEZE MAY DEVELOP AT KACY THIS AFTN. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE MOST OF THIS WEEK. AS HIGH SLOWLY MOVES OFF THE COAST. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. IT IS PSBL THAT THERE IS A BRIEF PD OF MVFR CIGS OR VSBYS IF THERE ARE ANY DECENT SHOWERS. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE BUILDS BACK IN. && .MARINE... A TRANQUIL FEW DAYS ARE IN STORE FOR THE AREA WATERS AS HIGH PRESSURE REMAINS IN CONTROL. LIGHT WINDS TODAY, GENLY 10 KT OR LESS WILL ALLOW FOR THE POSSIBILITY OF A SEA/BAY BREEZE AND S TO SW WINDS COULD BECOME SELY OR ELY. A RETURN TO MORE SWLY FLOW IS ANTICIPATED ON TUESDAY. NO MARINE FLAGS ARE ANTICIPATED MONDAY OR TUESDAY. A CDFNT WILL APPROACH FROM THE WEST AND CROSS THE WATERS ON WEDNESDAY. LATEST GUIDANCE INDICATES THAT SEAS COULD REACH SCA CRITERIA, ESPECIALLY OVER THE NRN WATERS. HOWEVER, WITH A WARM AMS IN PLACE, THE GUIDANCE MAY BE OVERDONE. NWLY FLOW WILL MOVE IN BEHIND THE DEPARTING FRONT. && .FIRE WEATHER... LOW PROBABILITY OF RED FLAG CONDITIONS IS OUTLOOKED IN THE 2 PM TO 8 PM TIME FRAME LATE WEDNESDAY AS GUSTY DRY CAA WINDS FOLLOW THE WEDNESDAY LATE MORNING CFP. NO ACTION ATTM DUE TO NORMAL UNCERTAINTIES WITH RH AND GUSTINESS MEETING CRITERIA AS WELL AS CONSULTING WITH FIRE OFFICIALS. HOWEVER... WE SHOULD HAVE NO PROBLEM MAINTAINING VERY DRY 10 HOUR FUELS. IT HASNT RAINED HERE BASICALLY IN THE THE 22ND-24TH WHICH IS 12 DAYS THROUGH YESTERDAY AND ADD A COUPLE OF DAYS /TODAY AND TUESDAY/ WHICH WILL MAKE IT 2 WEEKS OF DRY WEATHER! ANY SCATTERED SHOWERS WEDNESDAY MORNING WILL PROBABLY BE NEGLIGIBLE AND AND A NON FACTOR IN LIMITING INCREASED RATE OF SPREAD POTENTIAL. && .CLIMATE... JUST IN CASE...PRESUME ALL ARE AWARE OF THE 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 THE 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! && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...DRAG 419 SHORT TERM...DRAG 419 LONG TERM.../ DRAG 419 AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER... CLIMATE... 000 FXUS61 KPHI 060747 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 347 AM EDT MON SEP 6 2010 .SYNOPSIS... GENERALLY DRY WEATHER CONTINUES INTO THE START OF THE WEEKEND. COOL HIGH PRESSURE OVERHEAD WILL MERGE WITH THE BERMUDA HIGH ON TUESDAY PERMITTING A BRIEF RETURN OF VERY WARM AIR. WEDNESDAYS COLD FRONTAL PASSAGE MAY BE ACCOMPANIED BY A SHOWER OR SPRINKLE. LARGE AND COOL HIGH PRESSURE IN CENTRAL CANADA ARRIVES IN THE MID ATLANTIC STATES BY THIS WEEKEND WITH SEVERAL DAYS OF NEAR OR BELOW NORMAL TEMPERATURES BEGINNING ON THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 PM TEMP/DEWPOINT GRID TRENDS WERE UPDATED AND LOOKS LIKE SOMEWHAT HIGHER DEWPOINTS OVERNIGHT COULD RESULT IN 2MI SHALLOW GROUND FOG IN THE NEWTON TO SOMERVILLE NJ CORRIDOR NEAR DAWN LABOR DAY MORNING AS WELL AS IN PARTS OF SOUTHERN DEL AND E MD SHORE. APPARENTLY NOT ENOUGH FOG IN THE ZONES TO TRIGGER WORDING IN THE 1018PM ZFP OVERNIGHT UPDATE OTHERWISE HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION OVERNIGHT, WITH A MOSTLY CLEAR SKY AND A LIGHT WIND. TEMPERATURES ARE FORECAST TO DROP INTO THE 40S AND LOWER 50S AT MOST LOCATIONS, MAKING THIS THE COOLEST NIGHT SINCE THE SPRING. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TUE AND WED SFC TEMPS WILL PROBABLY BE RAISED 2-4 DEGS IN THE 4AM PKG. 00Z NAM CONFIRMS LIKELIHOOD OF ECMWF CORROBORATED 90+ PHL TO ACY. MONDAY - LABOR DAY...SEA BREEZES ARE AUTOMATIC IN THIS LIGHT WIND SITUATION. STILL IT WARMS UP FROM SUNDAYS VALUES BY 2-4 DEGS. OTRW ANOTHER SPECTACULAR LATE SUMMER DAY! MONDAY NIGHT...MAY BE A BIT BETTER CHANCE OF PATCHY FOG..AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A QUIET FEW DAYS ACRS THE AREA AS HIGH PRESSURE REMAINS IN CONTROL AND VFR CONDS PREVAIL. A S TO SW FLOW WILL OCCUR TODAY WITH SPEEDS GENLY 10 KTS OR LESS. WINDS WILL BECOME LIGHT OVERNIGHT, GENLY FROM THE S OR SW AND BECOME A BIT MORE SWLY ON TUESDAY, WITH SPEEDS GENLY IN THE 10 TO 15 KT RANGE. THERE WILL BE FEW IF ANY CLOUDS. WITH THE LIGHT FLOW, BIT OF A SEABREEZE MAY DEVELOP AT KACY THIS AFTN. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE MOST OF THIS WEEK. AS HIGH SLOWLY MOVES OFF THE COAST. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. IT IS PSBL THAT THERE IS A BRIEF PD OF MVFR CIGS OR VSBYS IF THERE ARE ANY DECENT SHOWERS. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE BUILDS BACK IN. && .MARINE... A TRANQUIL FEW DAYS ARE IN STORE FOR THE AREA WATERS AS HIGH PRESSURE REMAINS IN CONTROL. LIGHT WINDS TODAY, GENLY 10 KT OR LESS WILL ALLOW FOR THE POSSIBILITY OF A SEA/BAY BREEZE AND S TO SW WINDS COULD BECOME SELY OR ELY. A RETURN TO MORE SWLY FLOW IS ANTICIPATED ON TUESDAY. NO MARINE FLAGS ARE ANTICIPATED MONDAY OR TUESDAY. A CDFNT WILL APPROACH FROM THE WEST AND CROSS THE WATERS ON WEDNESDAY. LATEST GUIDANCE INDICATES THAT SEAS COULD REACH SCA CRITERIA, ESPECIALLY OVER THE NRN WATERS. HOWEVER, WITH A WARM AMS IN PLACE, THE GUIDANCE MAY BE OVERDONE. NWLY FLOW WILL MOVE IN BEHIND THE DEPARTING FRONT. && .FIRE WEATHER... LOW PROBABILITY OF RED FLAG CONDITIONS IS OUTLOOKED IN THE 2 PM TO 8 PM TIME FRAME LATE WEDNESDAY AS GUSTY DRY CAA WINDS FOLLOW THE WEDNESDAY LATE MORNING CFP. NO ACTION ATTM DUE TO NORMAL UNCERTAINTIES WITH RH AND GUSTINESS MEETING CRITERIA AS WELL AS CONSULTING WITH FIRE OFFICIALS. HOWEVER... WE SHOULD HAVE NO PROBLEM MAINTAINING VERY DRY 10 HOUR FUELS. IT HASNT RAINED HERE BASICALLY IN THE THE 22ND-24TH WHICH IS 12 DAYS THROUGH YESTERDAY AND ADD A COUPLE OF DAYS /TODAY AND TUESDAY/ WHICH WILL MAKE IT 2 WEEKS OF DRY WEATHER! ANY SCATTERED SHOWERS WEDNESDAY MORNING WILL PROBABLY BE NEGLIGIBLE AND AND A NON FACTOR IN LIMITING INCREASED RATE OF SPREAD POTENTIAL. && .CLIMATE... JUST IN CASE...PRESUME ALL ARE AWARE OF THE 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 THE 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! && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...DRAG WILL UPDATE AROUND 4A SHORT TERM...DRAG WILL UPDATE AROUND 4A LONG TERM.../ AVIATION...NIERENBERG 345A MARINE...NIERENBERG345A FIRE WEATHER...DRAG 345A CLIMATE... 000 FXUS61 KPHI 060711 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 311 AM EDT MON SEP 6 2010 .SYNOPSIS... GENERALLY DRY WEATHER CONTINUES INTO THE START OF THE WEEKEND. COOL HIGH PRESSURE OVERHEAD WILL MERGE WITH THE BERMUDA HIGH ON TUESDAY PERMITTING A BRIEF RETURN OF VERY WARM AIR. WEDNESDAYS COLD FRONTAL PASSAGE MAY BE ACCOMPANIED BY SCATTERED LIGHT SHOWERS BUT NO SIGNIFICANT RAIN IS ANTICIPATED. LARGE AND COOL HIGH PRESSURE IN CENTRAL CANADA THURSDAY ARRIVES IN THE MID ATLANTIC STATES BY THIS WEEKEND WITH AN EXTENDED PERIOD OF NEAR OR BELOW NORMAL TEMPERATURES THURSDAY INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 PM TEMP/DEWPOINT GRID TRENDS WERE UPDATED AND LOOKS LIKE SOMEWHAT HIGHER DEWPOINTS OVERNIGHT COULD RESULT IN 2MI SHALLOW GROUND FOG IN THE NEWTON TO SOMERVILLE NJ CORRIDOR NEAR DAWN LABOR DAY MORNING AS WELL AS IN PARTS OF SOUTHERN DEL AND E MD SHORE. APPARENTLY NOT ENOUGH FOG IN THE ZONES TO TRIGGER WORDING IN THE 1018PM ZFP OVERNIGHT UPDATE OTHERWISE HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION OVERNIGHT, WITH A MOSTLY CLEAR SKY AND A LIGHT WIND. TEMPERATURES ARE FORECAST TO DROP INTO THE 40S AND LOWER 50S AT MOST LOCATIONS, MAKING THIS THE COOLEST NIGHT SINCE THE SPRING. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TUE AND WED SFC TEMPS WILL PROBABLY BE RAISED 2-4 DEGS IN THE 4AM PKG. 00Z NAM CONFIRMS LIKELIHOOD OF ECMWF CORROBORATED 90+ PHL TO ACY. MONDAY - LABOR DAY...SEA BREEZES ARE AUTOMATIC IN THIS LIGHT WIND SITUATION. STILL IT WARMS UP FROM SUNDAYS VALUES BY 2-4 DEGS. OTRW ANOTHER SPECTACULAR LATE SUMMER DAY! MONDAY NIGHT...MAY BE A BIT BETTER CHANCE OF PATCHY FOG..AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. ABOUT NORMAL TEMPERATURES ARE FORECAST THROUGH THE LONG TERM PERIOD AS THE ZONAL PATTERN IS EXPECTED TO PRECLUDE MUCH DEVIATION FROM THE CLIMATOLOGICAL AVERAGE. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WINDS HAD LOWERED AT EARLY EVENING AS THE BOUNDARY LAYER WAS RAPIDLY DISCONNECTING FROM THE SURFACE...AND SURFACE HIGH PRESSURE CONTINUED TO BUILD EASTWARD OVER THE AREA. ONLY A FEW CIRRUS CLOUDS WERE SKIRTING THE SOUTHEASTERN PORTIONS OF OUR AREA...AND THESE SHOULD BE INNOCUOUS THIS EVENING. OTHERWISE WINDS WILL BE LIGHT AND VARIABLE OR CALM OVERNIGHT WITH CLEAR SKIES. THERE MAY BE A FEW CUMULUS MONDAY...BUT OTHERWISE FINE VFR FLYING CONDITIONS WILL PREVAIL. SURFACE WINDS ARE EXPECTED TO BE SOUTHWEST AT LESS THAN 10 KNOTS...OR EVEN SOUTHEAST TOWARD THE COAST INCLUDING KACY AS A BIT OF A SEA BREEZE DEVELOPS THERE BY MIDDAY. WINDS WILL LESSEN LATER IN THE AFTERNOON. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE THIS COMING WEEK. AS HIGH PRESSURE MOVES EASTWARD AND OFFSHORE MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND IS FORECAST TO INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE WILL LEAD TO SUB-SMALL CRAFT ADVISORY CONDITIONS TONIGHT AND MONDAY WITH WINDS EXPECTED TO BE 10 KNOTS OR LESS. GIVEN THE LIGHTER WINDS OF MONDAY, THOUGH, A SEA/BAY BREEZE CIRCULATION LOOKS TO BECOME ESTABLISHED. THIS WILL ALLOW THE WINDS TO TURN SOUTHERLY AND EVEN SOUTHEASTERLY. THE LOW-LEVEL FLOW IS FORECAST TO INCREASE TUESDAY WELL AHEAD OF AN ADVANCING COLD FRONT AND ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. GIVEN AN EVEN WARMER AIRMASS MOVING IN AND A SOUTHERLY WIND COMPONENT, THE WINDS ARE ANTICIPATED TO REMAIN UNDER ADVISORY CRITERIA. SOME ADDITIONAL INCREASE SHOULD TAKE PLACE WEDNESDAY AS THE COLD FRONT MOVES THROUGH. HOWEVER, GIVEN A LOW-LEVEL INVERSION FORECAST TO BE IN PLACE AHEAD OF THE FRONT, WE WILL CONTINUE TO KEEP WINDS... AND SEAS...BELOW ADVISORY CRITERIA. THE SOUTHERLY FLOW WILL BUILD THE SEAS SLIGHTLY. HOWEVER, BASED ON THE WIND TRAJECTORY SEAS WERE CAPPED AT 4 FEET. ONCE THE COLD FRONT MOVES THROUGH LATER WEDNESDAY, A WIND SHIFT TO THE NORTHWEST IS EXPECTED THROUGH THURSDAY. THIS WILL BRING IN COOLER AIR ALOFT, INCREASING THE DEPTH OF THE MIXED LAYER AND WINDS COULD NEAR ADVISORY CRITERIA FOR A TIME THURSDAY. HIGH PRESSURE WILL BUILD TOWARD THE AREA FRIDAY, WHICH WILL TEND TO WEAKEN THE PRESSURE GRADIENT. && .FIRE WEATHER... LOW PROB OF ELEVATED FIRE DANGER LATE WEDNESDAY AND THURSDAY. && .CLIMATE... PRESUME EVERYONE IS AWARE OF THE MARCH THROUGH AUGUST 2010 /6 MONTH 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 THE SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE AND LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! 2010 IS DEFINITELY SPECIAL YEAR HERE IN KPHI! WHAT MIGHT BE NEXT TO CLOSE OUT THE YEAR? && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG 309A NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM.../ AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER...309A CLIMATE...DRAG 000 FXUS61 KPHI 060306 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1106 PM EDT SUN SEP 5 2010 .SYNOPSIS... HIGH PRESSURE SLIDING TO THE MID ATLANTIC COAST THIS EVENING WILL MOVE OFFSHORE TONIGHT. DRY WEATHER WITH WARMING TEMPERATURES AND SLOWLY INCREASING HUMIDITY CAN BE EXPECTED MONDAY AND TUESDAY. A WEAK COLD FRONT WILL CROSS THE REGION WEDNESDAY...WITH LITTLE IN THE WAY OF SHOWER ACTIVITY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. AN UPPER AIR DISTURBANCE COULD BRING A FEW SHOWERS TO THE AREA NEXT WEEKEND. && .NEAR TERM /UNTIL 7 AM MONDAY MORNING/... 10 PM TEMP/DEWPOINT GRID TRENDS WERE UPDATED AND LOOKS LIKE SOMEWHAT HIGHER DEWPOINTS OVERNIGHT COULD RESULT IN 2MI SHALLOW GROUND FOG IN THE NEWTON TO SOMERVILLE NJ CORRIDOR NEAR DAWN LABOR DAY MORNING AS WELL AS IN PARTS OF SOUTHERN DEL AND E MD SHORE. APPARENTLY NOT ENOUGH FOG IN THE ZONES TO TRIGGER WORDING IN THE 1018PM ZFP OVERNIGHT UPDATE OTHERWISE HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION OVERNIGHT, WITH A MOSTLY CLEAR SKY AND A LIGHT WIND. TEMPERATURES ARE FORECAST TO DROP INTO THE 40S AND LOWER 50S AT MOST LOCATIONS, MAKING THIS THE COOLEST NIGHT SINCE THE SPRING. && .SHORT TERM /7 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/... TUE AND WED SFC TEMPS WILL PROBABLY BE RAISED 2-4 DEGS IN THE 4AM PKG. 00Z NAM CONFIRMS LIKELIHOOD OF ECMWF CORROBORATED 90+ PHL TO ACY. MONDAY - LABOR DAY...SEA BREEZES ARE AUTOMATIC IN THIS LIGHT WIND SITUATION. STILL IT WARMS UP FROM SUNDAYS VALUES BY 2-4 DEGS. OTRW ANOTHER SPECTACULAR LATE SUMMER DAY! MONDAY NIGHT...MAY BE A BIT BETTER CHANCE OF PATCHY FOG..AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. && .LONG TERM /THURSDAY THROUGH SUNDAY/... STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. ABOUT NORMAL TEMPERATURES ARE FORECAST THROUGH THE LONG TERM PERIOD AS THE ZONAL PATTERN IS EXPECTED TO PRECLUDE MUCH DEVIATION FROM THE CLIMATOLOGICAL AVERAGE. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WINDS HAD LOWERED AT EARLY EVENING AS THE BOUNDARY LAYER WAS RAPIDLY DISCONNECTING FROM THE SURFACE...AND SURFACE HIGH PRESSURE CONTINUED TO BUILD EASTWARD OVER THE AREA. ONLY A FEW CIRRUS CLOUDS WERE SKIRTING THE SOUTHEASTERN PORTIONS OF OUR AREA...AND THESE SHOULD BE INNOCUOUS THIS EVENING. OTHERWISE WINDS WILL BE LIGHT AND VARIABLE OR CALM OVERNIGHT WITH CLEAR SKIES. THERE MAY BE A FEW CUMULUS MONDAY...BUT OTHERWISE FINE VFR FLYING CONDITIONS WILL PREVAIL. SURFACE WINDS ARE EXPECTED TO BE SOUTHWEST AT LESS THAN 10 KNOTS...OR EVEN SOUTHEAST TOWARD THE COAST INCLUDING KACY AS A BIT OF A SEA BREEZE DEVELOPS THERE BY MIDDAY. WINDS WILL LESSEN LATER IN THE AFTERNOON. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE THIS COMING WEEK. AS HIGH PRESSURE MOVES EASTWARD AND OFFSHORE MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND IS FORECAST TO INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE WILL LEAD TO SUB-SMALL CRAFT ADVISORY CONDITIONS TONIGHT AND MONDAY WITH WINDS EXPECTED TO BE 10 KNOTS OR LESS. GIVEN THE LIGHTER WINDS OF MONDAY, THOUGH, A SEA/BAY BREEZE CIRCULATION LOOKS TO BECOME ESTABLISHED. THIS WILL ALLOW THE WINDS TO TURN SOUTHERLY AND EVEN SOUTHEASTERLY. THE LOW-LEVEL FLOW IS FORECAST TO INCREASE TUESDAY WELL AHEAD OF AN ADVANCING COLD FRONT AND ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. GIVEN AN EVEN WARMER AIRMASS MOVING IN AND A SOUTHERLY WIND COMPONENT, THE WINDS ARE ANTICIPATED TO REMAIN UNDER ADVISORY CRITERIA. SOME ADDITIONAL INCREASE SHOULD TAKE PLACE WEDNESDAY AS THE COLD FRONT MOVES THROUGH. HOWEVER, GIVEN A LOW-LEVEL INVERSION FORECAST TO BE IN PLACE AHEAD OF THE FRONT, WE WILL CONTINUE TO KEEP WINDS... AND SEAS...BELOW ADVISORY CRITERIA. THE SOUTHERLY FLOW WILL BUILD THE SEAS SLIGHTLY. HOWEVER, BASED ON THE WIND TRAJECTORY SEAS WERE CAPPED AT 4 FEET. ONCE THE COLD FRONT MOVES THROUGH LATER WEDNESDAY, A WIND SHIFT TO THE NORTHWEST IS EXPECTED THROUGH THURSDAY. THIS WILL BRING IN COOLER AIR ALOFT, INCREASING THE DEPTH OF THE MIXED LAYER AND WINDS COULD NEAR ADVISORY CRITERIA FOR A TIME THURSDAY. HIGH PRESSURE WILL BUILD TOWARD THE AREA FRIDAY, WHICH WILL TEND TO WEAKEN THE PRESSURE GRADIENT. && .CLIMATE... PRESUME EVERYONE IS AWARE OF THE MARCH THROUGH AUGUST 2010 /6 MONTH 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 THE SOURCE IS THE NORTHEAST REGIONAL CLIMATE CENTER AND THIS INFORMATION IS FOUND ON THEIR HOMEPAGE AND LISTS NUMEROUS CITIES FROM NEW ENGLAND THROUGH THE MID ATLC STATES WITH THE RECORDS FOR THIS 6 MONTH PERIOD! 2010 IS DEFINITELY SPECIAL YEAR HERE IN KPHI! WHAT MIGHT BE NEXT TO CLOSE OUT THE YEAR? && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...HAYES NEAR TERM...DRAG 1105P SHORT TERM...DRAG/HAYES LONG TERM... AVIATION... MARINE... CLIMATE...1105 P 000 FXUS61 KPHI 060220 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1020 PM EDT SUN SEP 5 2010 .SYNOPSIS... HIGH PRESSURE SLIDING TO THE MID ATLANTIC COAST THIS EVENING WILL MOVE OFFSHORE TONIGHT. DRY WEATHER WITH WARMING TEMPERATURES AND SLOWLY INCREASING HUMIDITY CAN BE EXPECTED MONDAY AND TUESDAY. A WEAK COLD FRONT WILL CROSS THE REGION WEDNESDAY...WITH LITTLE IN THE WAY OF SHOWER ACTIVITY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. AN UPPER AIR DISTURBANCE COULD BRING A FEW SHOWERS TO THE AREA NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 10 PM TEMP/DEWPOINT GRID TRENDS WERE UPDATED AND LOOKS LIKE SOMEWHAT HIGHER DEWPOINTS OVERNIGHT COULD RESULT IN 2MI SHALLOW GROUND FOG IN THE NEWTON TO SOMERVILLE NJ CORRIDOR NEAR DAWN LABOR DAY MORNING AS WELL AS IN PARTS OF SOUTHERN DEL AND E MD SHORE. APPARENTLY NOT ENOUGH FOG IN THE ZONES TO TRIGGER WORDING IN THE 1018PM ZFP OVERNIGHT UPDATE OTHERWISE HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION OVERNIGHT, WITH A MOSTLY CLEAR SKY AND A LIGHT WIND. TEMPERATURES ARE FORECAST TO DROP INTO THE 40S AND LOWER 50S AT MOST LOCATIONS, MAKING THIS THE COOLEST NIGHT SINCE THE SPRING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... AS THE SURFACE HIGH GETS OFF THE MID ATLANTIC COAST...THE DEVELOPING RETURN FLOW WILL START BRINGING IN WARMER AND EVENTUALLY MORE LOW LEVEL MOISTURE. A BIT MORE IN THE WAY OF LOW LEVEL MOISTURE MAY ALLOW JUST A BIT MORE IN THE WAY OF CUMULUS ACROSS SOUTHERN AREAS. THE EXITING MID LEVEL TROUGH (AND WARMER MID LEVEL TEMPERATURES) SHOULD RESULT IN LESS CUMULUS NORTH. MODELS ARE SHOWING MID LEVEL CLOUDINESS MOVING BY TO THE NORTH AS A SHORT WAVE IN THE MID LEVEL FLOW FOLLOWED THE LONG WAVE TROUGH OUT TO THE EAST. THIS COULD RESULT IN PARTLY SUNNY SKIES NORTH DURING THE AFTERNOON. AFTER A COOL START...HIGHS SHOULD REBOUND BACK TO THE SLIGHTLY COOLER NAM MOS NUMBERS. THE WEAKENING SURFACE GRADIENT SHOULD ALLOW SEA AND BAY BREEZES TO DEVELOP IN THE AFTERNOON. MAY BE A BIT BETTER CHANCE OF PATCHY FOG MONDAY NIGHT...AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. AFTER THIS WAVE PASSES...STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. ABOUT NORMAL TEMPERATURES ARE FORECAST THROUGH THE LONG TERM PERIOD AS THE ZONAL PATTERN IS EXPECTED TO PRECLUDE MUCH DEVIATION FROM THE CLIMATOLOGICAL AVERAGE. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WINDS HAD LOWERED AT EARLY EVENING AS THE BOUNDARY LAYER WAS RAPIDLY DISCONNECTING FROM THE SURFACE...AND SURFACE HIGH PRESSURE CONTINUED TO BUILD EASTWARD OVER THE AREA. ONLY A FEW CIRRUS CLOUDS WERE SKIRTING THE SOUTHEASTERN PORTIONS OF OUR AREA...AND THESE SHOULD BE INNOCUOUS THIS EVENING. OTHERWISE WINDS WILL BE LIGHT AND VARIABLE OR CALM OVERNIGHT WITH CLEAR SKIES. THERE MAY BE A FEW CUMULUS MONDAY...BUT OTHERWISE FINE VFR FLYING CONDITIONS WILL PREVAIL. SURFACE WINDS ARE EXPECTED TO BE SOUTHWEST AT LESS THAN 10 KNOTS...OR EVEN SOUTHEAST TOWARD THE COAST INCLUDING KACY AS A BIT OF A SEA BREEZE DEVELOPS THERE BY MIDDAY. WINDS WILL LESSEN LATER IN THE AFTERNOON. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE THIS COMING WEEK. AS HIGH PRESSURE MOVES EASTWARD AND OFFSHORE MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND IS FORECAST TO INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE WILL LEAD TO SUB-SMALL CRAFT ADVISORY CONDITIONS TONIGHT AND MONDAY WITH WINDS EXPECTED TO BE 10 KNOTS OR LESS. GIVEN THE LIGHTER WINDS OF MONDAY, THOUGH, A SEA/BAY BREEZE CIRCULATION LOOKS TO BECOME ESTABLISHED. THIS WILL ALLOW THE WINDS TO TURN SOUTHERLY AND EVEN SOUTHEASTERLY. THE LOW-LEVEL FLOW IS FORECAST TO INCREASE TUESDAY WELL AHEAD OF AN ADVANCING COLD FRONT AND ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. GIVEN AN EVEN WARMER AIRMASS MOVING IN AND A SOUTHERLY WIND COMPONENT, THE WINDS ARE ANTICIPATED TO REMAIN UNDER ADVISORY CRITERIA. SOME ADDITIONAL INCREASE SHOULD TAKE PLACE WEDNESDAY AS THE COLD FRONT MOVES THROUGH. HOWEVER, GIVEN A LOW-LEVEL INVERSION FORECAST TO BE IN PLACE AHEAD OF THE FRONT, WE WILL CONTINUE TO KEEP WINDS... AND SEAS...BELOW ADVISORY CRITERIA. THE SOUTHERLY FLOW WILL BUILD THE SEAS SLIGHTLY. HOWEVER, BASED ON THE WIND TRAJECTORY SEAS WERE CAPPED AT 4 FEET. ONCE THE COLD FRONT MOVES THROUGH LATER WEDNESDAY, A WIND SHIFT TO THE NORTHWEST IS EXPECTED THROUGH THURSDAY. THIS WILL BRING IN COOLER AIR ALOFT, INCREASING THE DEPTH OF THE MIXED LAYER AND WINDS COULD NEAR ADVISORY CRITERIA FOR A TIME THURSDAY. HIGH PRESSURE WILL BUILD TOWARD THE AREA FRIDAY, WHICH WILL TEND TO WEAKEN THE PRESSURE GRADIENT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...HAYES NEAR TERM...DRAG 1020P SHORT TERM...HAYES LONG TERM... AVIATION... MARINE... 000 FXUS61 KPHI 060015 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 815 PM EDT SUN SEP 5 2010 .SYNOPSIS... HIGH PRESSURE SLIDING TO THE MID ATLANTIC COAST THIS EVENING WILL MOVE OFFSHORE TONIGHT. DRY WEATHER WITH WARMING TEMPERATURES AND SLOWLY INCREASING HUMIDITY CAN BE EXPECTED MONDAY AND TUESDAY. A WEAK COLD FRONT WILL CROSS THE REGION WEDNESDAY...WITH LITTLE IN THE WAY OF SHOWER ACTIVITY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. AN UPPER AIR DISTURBANCE COULD BRING A FEW SHOWERS TO THE AREA NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AT 800 PM, THE SKY OVER OUR REGION WAS MAINLY CLEAR, WITH A LITTLE CIRRUS OVER SOUTHERN DELAWARE AND SOUTHEASTERN NEW JERSEY. TEMPERATURES WERE MOSTLY IN THE 60S AND LOWER 70S, WITH SOME READINGS ALREADY DOWN INTO THE 50S UP NORTH. HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION OVERNIGHT, WITH A MOSTLY CLEAR SKY AND A LIGHT WIND. TEMPERATURES ARE FORECAST TO DROP INTO THE 40S AND LOWER 50S AT MOST LOCATIONS, MAKING THIS THE COOLEST NIGHT SINCE THE SPRING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... AS THE SURFACE HIGH GETS OFF THE MID ATLANTIC COAST...THE DEVELOPING RETURN FLOW WILL START BRINGING IN WARMER AND EVENTUALLY MORE LOW LEVEL MOISTURE. A BIT MORE IN THE WAY OF LOW LEVEL MOISTURE MAY ALLOW JUST A BIT MORE IN THE WAY OF CUMULUS ACROSS SOUTHERN AREAS. THE EXITING MID LEVEL TROUGH (AND WARMER MID LEVEL TEMPERATURES) SHOULD RESULT IN LESS CUMULUS NORTH. MODELS ARE SHOWING MID LEVEL CLOUDINESS MOVING BY TO THE NORTH AS A SHORT WAVE IN THE MID LEVEL FLOW FOLLOWED THE LONG WAVE TROUGH OUT TO THE EAST. THIS COULD RESULT IN PARTLY SUNNY SKIES NORTH DURING THE AFTERNOON. AFTER A COOL START...HIGHS SHOULD REBOUND BACK TO THE SLIGHTLY COOLER NAM MOS NUMBERS. THE WEAKENING SURFACE GRADIENT SHOULD ALLOW SEA AND BAY BREEZES TO DEVELOP IN THE AFTERNOON. MAY BE A BIT BETTER CHANCE OF PATCHY FOG MONDAY NIGHT...AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. AFTER THIS WAVE PASSES...STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. ABOUT NORMAL TEMPERATURES ARE FORECAST THROUGH THE LONG TERM PERIOD AS THE ZONAL PATTERN IS EXPECTED TO PRECLUDE MUCH DEVIATION FROM THE CLIMATOLOGICAL AVERAGE. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WINDS HAD LOWERED AT EARLY EVENING AS THE BOUNDARY LAYER WAS RAPIDLY DISCONNECTING FROM THE SURFACE...AND SURFACE HIGH PRESSURE CONTINUED TO BUILD EASTWARD OVER THE AREA. ONLY A FEW CIRRUS CLOUDS WERE SKIRTING THE SOUTHEASTERN PORTIONS OF OUR AREA...AND THESE SHOULD BE INNOCUOUS THIS EVENING. OTHERWISE WINDS WILL BE LIGHT AND VARIABLE OR CALM OVERNIGHT WITH CLEAR SKIES. THERE MAY BE A FEW CUMULUS MONDAY...BUT OTHERWISE FINE VFR FLYING CONDITIONS WILL PREVAIL. SURFACE WINDS ARE EXPECTED TO BE SOUTHWEST AT LESS THAN 10 KNOTS...OR EVEN SOUTHEAST TOWARD THE COAST INCLUDING KACY AS A BIT OF A SEA BREEZE DEVELOPS THERE BY MIDDAY. WINDS WILL LESSEN LATER IN THE AFTERNOON. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO RULE THIS COMING WEEK. AS HIGH PRESSURE MOVES EASTWARD AND OFFSHORE MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND IS FORECAST TO INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA DURING WEDNESDAY...AND THERE IS ONLY A SLIGHT CHANCE OF SHOWERS THEN. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS FORECAST FOR THURSDAY AND FRIDAY...PROBABLY SOMEWHAT GUSTY AT LEAST EARLY THURSDAY...AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE WILL LEAD TO SUB-SMALL CRAFT ADVISORY CONDITIONS TONIGHT AND MONDAY WITH WINDS EXPECTED TO BE 10 KNOTS OR LESS. GIVEN THE LIGHTER WINDS OF MONDAY, THOUGH, A SEA/BAY BREEZE CIRCULATION LOOKS TO BECOME ESTABLISHED. THIS WILL ALLOW THE WINDS TO TURN SOUTHERLY AND EVEN SOUTHEASTERLY. THE LOW-LEVEL FLOW IS FORECAST TO INCREASE TUESDAY WELL AHEAD OF AN ADVANCING COLD FRONT AND ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. GIVEN AN EVEN WARMER AIRMASS MOVING IN AND A SOUTHERLY WIND COMPONENT, THE WINDS ARE ANTICIPATED TO REMAIN UNDER ADVISORY CRITERIA. SOME ADDITIONAL INCREASE SHOULD TAKE PLACE WEDNESDAY AS THE COLD FRONT MOVES THROUGH. HOWEVER, GIVEN A LOW-LEVEL INVERSION FORECAST TO BE IN PLACE AHEAD OF THE FRONT, WE WILL CONTINUE TO KEEP WINDS... AND SEAS...BELOW ADVISORY CRITERIA. THE SOUTHERLY FLOW WILL BUILD THE SEAS SLIGHTLY. HOWEVER, BASED ON THE WIND TRAJECTORY SEAS WERE CAPPED AT 4 FEET. ONCE THE COLD FRONT MOVES THROUGH LATER WEDNESDAY, A WIND SHIFT TO THE NORTHWEST IS EXPECTED THROUGH THURSDAY. THIS WILL BRING IN COOLER AIR ALOFT, INCREASING THE DEPTH OF THE MIXED LAYER AND WINDS COULD NEAR ADVISORY CRITERIA FOR A TIME THURSDAY. HIGH PRESSURE WILL BUILD TOWARD THE AREA FRIDAY, WHICH WILL TEND TO WEAKEN THE PRESSURE GRADIENT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...HAYES NEAR TERM...IOVINO SHORT TERM...HAYES 000 FXUS61 KPHI 051858 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 258 PM EDT SUN SEP 5 2010 .SYNOPSIS... HIGH PRESSURE SLIDING TO THE MID ATLANTIC COAST THIS EVENING WILL MOVE OFFSHORE TONIGHT. DRY WEATHER WITH WARMING TEMPERATURES AND SLOWLY INCREASING HUMIDITY CAN BE EXPECTED MONDAY AND TUESDAY. A WEAK COLD FRONT WILL CROSS THE REGION WEDNESDAY...WITH LITTLE IN THE WAY OF SHOWER ACTIVITY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. AN UPPER AIR DISTURBANCE COULD BRING A FEW SHOWERS TO THE AREA NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE LAST OF THE GRADIENT SHOULD DROP OFF THIS EVENING AS THE SURFACE HIGH BUILDS TO THE MID ATLANTIC COAST. THE LOSS OF DAYTIME HEATING SHOULD ALLOW THE CUMULUS TO DISSIPATE...WITH JUST A FEW WISPS OF CIRRUS ACROSS SOUTHERN AREAS THIS EVENING. OTHERWISE...TONIGHT APPEARS TO BE A VERY GOOD RADIATIONAL COOLING NIGHT. FOR THE MOST PART...USED A BLEND OF MOS NUMBERS FOR LOWS. HOWEVER..FOR SOME OF THE COLDER LOCATIONS (WHICH DIPPED 3 TO 5 DEGREES UNDER THE COOLEST MOS FOR EARLY THIS MORNING)...WILL UNDERCUT EVEN THESE NUMBERS. STILL APPEARS AS THOUGH THE AIRMASS IS STILL TOO DRY TO SUPPORT PATCHY FOG AWAY FROM WARM BODIES OF WATER. BASED ON THIS...WILL LEAVE THE MENTION FOG OUT FOR THE OVERNIGHT...AS IT APPEARS AS THOUGH IT WILL NOT BE PREVALENT ENOUGH TO MENTION. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... AS THE SURFACE HIGH GETS OFF THE MID ATLANTIC COAST...THE DEVELOPING RETURN FLOW WILL START BRINGING IN WARMER AND EVENTUALLY MORE LOW LEVEL MOISTURE. A BIT MORE IN THE WAY OF LOW LEVEL MOISTURE MAY ALLOW JUST A BIT MORE IN THE WAY OF CUMULUS ACROSS SOUTHERN AREAS. THE EXITING MID LEVEL TROUGH (AND WARMER MID LEVEL TEMPERATURES) SHOULD RESULT IN LESS CUMULUS NORTH. MODELS ARE SHOWING MID LEVEL CLOUDINESS MOVING BY TO THE NORTH AS A SHORT WAVE IN THE MID LEVEL FLOW FOLLOWED THE LONG WAVE TROUGH OUT TO THE EAST. THIS COULD RESULT IN PARTLY SUNNY SKIES NORTH DURING THE AFTERNOON. AFTER A COOL START...HIGHS SHOULD REBOUND BACK TO THE SLIGHTLY COOLER NAM MOS NUMBERS. THE WEAKENING SURFACE GRADIENT SHOULD ALLOW SEA AND BAY BREEZES TO DEVELOP IN THE AFTERNOON. MAY BE A BIT BETTER CHANCE OF PATCHY FOG MONDAY NIGHT...AS THE LOW LEVELS WARM AND MOISTEN. OTHER THAN THAT...NOT MUCH IN THE WAY OF CLOUDINESS AS THE MID LEVEL RIDGE POKES NORTH FROM THE MID ATLANTIC. NOT NEARLY AS COOL MONDAY NIGHT AS A RESULT...AND LOWS SHOULD BE CLOSE TO THE MOS BLEND. DEW POINTS WILL BE ON THE RISE TUESDAY...AS THE MID LEVEL RIDGE COVERS THE FORECAST AREA. PROBABLY NOT ENOUGH MOISTURE FOR MORE THAN SCATTERED CUMULUS. WHILE THE LOW LEVEL HUMIDITY INCREASES...THERE DOES NOT APPEAR TO BE ENOUGH FOR EVEN MARGINAL INSTABILITY TUESDAY...SO WILL KEEP IT DRY. 850 MB TEMPERATURES REACH NEAR 16 DEGREES CELSIUS. THIS COULD SUPPORT A FEW 90 DEGREE READINGS AWAY FROM THE SEA/BAY BREEZES. HOWEVER... DEW POINT SHOULD HAVE ONLY RISEN BACK TO ABOUT 60...SO THE HEAT INDEX VALUES COULD BE THE SAME AS THE AIR TEMPERATURE. MODELS START TO DIVERGE TUESDAY NIGHT AS THE FASTER 1200 UTC GFS BRINGS A SHORT WAVE ACROSS THE GREAT LAKES. THE 1200 UTC NAM AND ECMWF ARE ABOUT 3 TO 6 HOURS SLOWER WITH THIS FEATURE...AND ARE SLOWER TO MOISTEN THE LOWER TO MID LEVELS AS A RESULT. THE LOW TO MID LEVEL WARM AIR ADVECTION IS STRONG...SO THERE IS SUPPORT FOR CLOUDS NORTH. HOWEVER...AT THIS POINT...IT APPEARS AS THOUGH THE BEST LIFT REMAINS NORTH OF THE REGION. BASED ON THIS...WILL KEEP THE FORECAST DRY FOR TUESDAY NIGHT. THE 1200 UTC GFS SEEMS TOO FAST BRINGING THE COLD FRONT THROUGH WEDNESDAY MORNING...AS THE MID LEVEL SUPPORT APPEARS TO SHEAR OUT TO THE NORTHEAST. LIKE THE TIMING OF THE 1200 NAM A BIT MORE...WHICH IS ABOUT 3 TO 6 HOURS SLOWER. THE SENSIBLE WEATHER DIFFERENCE MAY BE LIMITED TO THE WIND SHIFT WITH THE FRONT...AS THE LOW LEVEL MOISTURE AHEAD OF THE FRONT IS DEEP ENOUGH FOR MUCH IN THE WAY OF SHALLOW CONVECTION. FOR NOW...WILL KEEP THE FORECAST DRY WITH THE FRONTAL PASSAGE (WE ARE GETTING TO THE TIME OF YEAR). && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... A MODERATE SHORT WAVE RUNNING THROUGH THE NORTHERN TIER OF STATES EARLY THIS WEEK IS FORECAST TO FLATTEN SOMEWHAT AS IT MAKES IT TO OUR LONGITUDE...WITH THE GREATEST IMPACTS NORTH OF OUR REGION. THE ASSOCIATED SURFACE FRONT APPEARS A BIT FASTER THAN PREVIOUS MODEL RUNS...SO DRY WEATHER WILL BE FORECAST TO START THE LONG TERM PERIOD WEDNESDAY NIGHT AS THE MODEST FORCING ASSOCIATED WITH THIS SYSTEM WILL HOPEFULLY HAVE MOVED PAST. AFTER THIS WAVE PASSES...STRONG UPPER RIDGING AND SURFACE HIGH PRESSURE ARE PROGGED FOR THE END OF THE WEEK...LEADING TO DRY WEATHER. HOWEVER, ANOTHER SHORT WAVE MAINLY NORTH OF OUR LATITUDE APPEARS ON THE HORIZON FOR ABOUT SATURDAY...WHICH IS ALSO A LITTLE EARLIER THAN PREVIOUS MODEL RUNS HAD INDICATED. SLIGHT CHANCE TO LOW CHANCE PROBABILITIES FOR SHOWERS WILL BE INCLUDED FOR NOW FOR SATURDAY AND EARLY SATURDAY EVENING...WITH AN OPTIMISTIC DRY FORECAST FOR SUNDAY AT THIS POINT. ABOUT NORMAL TEMPERATURES ARE FORECAST THROUGH THE LONG TERM PERIOD AS THE ZONAL PATTERN IS EXPECTED TO PRECLUDE MUCH DEVIATION FROM THE CLIMATOLOGICAL AVERAGE. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. HIGH PRESSURE STRETCHED FROM THE UPPER OHIO VALLEY TO THE SOUTHERN MID ATLANTIC COAST WILL GRADUALLY SLIDE EASTWARD TONIGHT AND MONDAY. A RATHER DRY AIRMASS CONTINUES TO BE IN PLACE, HOWEVER WITH THE DAYTIME HEATING SOME STRATOCUMULUS/CUMULUS HAVE DEVELOPED BUT THE COVERAGE IS MUCH LESS THAN WHAT WAS OBSERVED YESTERDAY. WE CONTINUED TO PLACE THE GREATER COVERAGE /SCATTERED/ AT KABE AND KRDG INTO THIS EVENING, ALTHOUGH SATELLITE IMAGERY TRENDS INDICATE THAT THE SOUTHERN EDGE OF THE CLOUD MASS IS ERODING AS IT TRIES TO MOVE FATHER SOUTHEASTWARD. THE PRESSURE GRADIENT IS MUCH WEAKER THIS AFTERNOON COMPARED TO YESTERDAY, BUT THERE HAS BEEN ENOUGH VERTICAL MIXING TO ALLOW SOME GUSTS TO NEAR 20 KNOTS THIS AFTERNOON HOWEVER THERE IS A DOWNWARD TREND TO THIS. AT MOST OF THE TERMINALS, WE OPTED TO GO WITH A SLIGHTLY HIGHER SUSTAINED WIND INTO THIS EVENING WITH NO GUSTS INDICATED GIVEN A DOWNWARD TREND IN THE OVERALL WESTERLY WINDS. ANY LINGERING CLOUDS WILL DISSIPATE THROUGH THE EVENING AND THE WINDS ARE EXPECTED TO GO LIGHT AND VARIABLE TO CALM AT ALL OUR TERMINALS OVERNIGHT. FOR MONDAY, HIGH PRESSURE SETTLES ACROSS OUR AREA BUT WILL ALSO BE GRADUALLY SHIFTING TO THE EAST. THIS WILL ALLOW A LIGHT AND VARIABLE WIND TO INCREASE TO NEAR 10 KNOTS AND BECOME SOUTHWESTERLY. IT IS FORECAST TO BE WARMER MONDAY AFTERNOON, AND WITH THE LIGHTER WINDS, A SEA BREEZE SHOULD DEVELOP AND GET TO KACY. LITTLE IN THE WAY OF CLOUDS ARE ANTICIPATED, THEREFORE VFR CONDITIONS ARE FORECAST TO PREVAIL. OUTLOOK... AS HIGH PRESSURE SLIDES TO OUR EAST MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND WILL INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA DURING WEDNESDAY AND THERE IS SMALL CHANCE A FEW SHOWERS ACCOMPANY IT. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS THEN FORECAST FOR THURSDAY AND FRIDAY AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE STRETCHED FROM THE UPPER OHIO VALLEY TO THE SOUTHERN MID ATLANTIC STATES THIS AFTERNOON WILL CONTINUE TO SLIDE EASTWARD DURING THE NEXT FEW DAYS. THIS HAS ALLOWED THE PRESSURE GRADIENT TO WEAKEN AND THE SURFACE OBSERVATIONS ARE INDICATING THE WINDS DECREASING ON SCHEDULE. THE LESSENING OF THE WINDS ACROSS THE FAR SOUTHERN WATERS IS ACTUALLY ALLOWING THE DIRECTION TO SHIFT TO THE EAST AND SOUTHEAST. OVERALL, THE WINDS ARE EXPECTED TO BE 10 KNOTS OR LESS TONIGHT AND MONDAY AS HIGH PRESSURE MOVES OVER THE REGION. GIVEN THE LIGHTER WINDS ON MONDAY THOUGH, A SEA/BAY BREEZE CIRCULATION LOOKS TO BECOME ESTABLISHED. THIS WILL ALLOW THE WINDS TO TURN SOUTHERLY AND EVEN SOUTHEASTERLY. THE LOW-LEVEL FLOW IS FORECAST TO INCREASE TUESDAY WELL AHEAD OF AN ADVANCING COLD FRONT AND ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. GIVEN AN EVEN WARMER AIRMASS MOVING IN AND A SOUTHERLY WIND COMPONENT, THE WINDS ARE ANTICIPATED TO REMAIN UNDER ADVISORY CRITERIA. SOME ADDITIONAL INCREASE SHOULD TAKE PLACE WEDNESDAY AS THE COLD FRONT MOVES THROUGH. HOWEVER GIVEN A LOW-LEVEL INVERSION FORECAST TO BE IN PLACE AHEAD OF THE FRONT, WE WILL CONTINUE TO KEEP WINDS BELOW ADVISORY CRITERIA. THE SOUTHERLY FLOW WILL BUILD THE SEAS, HOWEVER BASED ON THE WIND TRAJECTORY WE CAPPED THE SEAS AT 4 FEET. ONCE THE COLD FRONT MOVES THROUGH LATER WEDNESDAY, A WIND SHIFT TO THE NORTHWEST IS EXPECTED THROUGH THURSDAY. THIS WILL BRING IN COOLER AIR ALOFT, INCREASING THE DEPTH OF THE MIXED LAYER AND WINDS COULD NEAR ADVISORY CRITERIA FOR A TIME THURSDAY. HIGH PRESSURE BUILDS TOWARD THE AREA FRIDAY, WHICH WILL TEND TO WEAKEN THE PRESSURE GRADIENT. && .FIRE WEATHER... BASED ON THE AMDAR SOUNDINGS FROM THE KPHL AREA EARLY THIS AFTERNOON...THE WINDS AT THE TOP OF THE MIXED LAYER (ABOUT 5000 FEET) HAVE DROPPED BELOW 20 KNOTS. THIS MAKES SENSE AS THE LAST OF THE COLD AIR ADVECTION ENDS AND THE GRADIENT WEAKENS. AT THE SAME TIME...THE DRIER AIR FROM AROUND 850 MB HAS MIXED TO THE SURFACE...AND ALLOWED SURFACE DEW POINTS TO DROP INTO THE UPPER 30S AND LOWER 40S. THIS HAS RESULTED IN RELATIVE HUMIDITY VALUES DROPPING TO NEAR 30 PERCENT. THE COMBINATION OF WIND AND MINIMUM RELATIVE HUMIDITY HAS REMAINED ABOVE RED FLAG CRITERIA. CONDITIONS SHOULD IMPROVE AS THE WIND BACKS OFF. AS THE SURFACE HIGH GETS OFFSHORE MONDAY...WINDS BACK AROUND TO SOUTHWEST (AND SOUTH NEAR THE WATER). WIND SPEEDS SHOULD NOT EXCEED 10 KNOTS IN MOST PLACES...AND HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT. WITH HIGH HUMIDITIES MONDAY AND TUESDAY...NOT EXPECTING TO DROP BACK TOWARD RED FLAG WARNING NUMBERS EITHER DAY. && .RIP CURRENTS... THE WAVE ACTION IN THE SURF ZONE CONTINUES TO LOWER /NOW ABOUT 2 FEET/ AS THE WIND HAS SUBSIDED AND THE OCEAN OVERALL HAS SETTLED DOWN. WE MADE CALLS THIS AFTERNOON TO SOME OF THE BEACH PATROLS AND THEY REPORTED THAT THE CONDITIONS HAVE IMPROVED WITH NO MAJOR ISSUES NOTED. AS A RESULT, WE WILL ALLOW THE MODERATE RISK OF RIP CURRENTS TO EXPIRE EARLY THIS EVENING. BASED ON THE REPORTS THIS AFTERNOON AND FORECAST CONDITIONS FOR LABOR DAY, THE RIP CURRENT RISK APPEARS TO BE LOW. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES LONG TERM.../ AVIATION...GORSE MARINE...GORSE FIRE WEATHER...HAYES RIP CURRENTS...GORSE 000 FXUS61 KPHI 051740 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 140 PM EDT SUN SEP 5 2010 .SYNOPSIS... GENERALLY RAIN FREE WEATHER IS FEATURED INTO AT LEAST THE START OF THIS COMING WEEKEND AS LOW PRESSURE SYSTEMS MOVING INTO SOUTHEAST CANADA ARE THE PRIMARY INFLUENCE UPON OUR WEATHER. REFRESHINGLY COOL HIGH PRESSURE BUILDING EAST INTO THE MID ATLANTIC STATES TODAY BECOMES PART OF THE BERMUDA HIGH ON MONDAY PERMITTING A BRIEF WARM UP TUESDAY AND WEDNESDAY. AFTER A COLD FRONT CROSSES THE REGION WEDNESDAY...COOL CENTRAL CANADA HIGH PRESSURE FOLLOWS... EVENTUALLY SETTLING INTO THE MID ATLANTIC STATES BY NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NOT MUCH CHANGE FROM THE PREVIOUS FORECAST THIS MORNING. 1200 UTC SOUNDINGS SUGGEST THAT NORTHERN AREAS HAVE A BETTER CHANCE OF REACHING CONVECTIVE TEMPERATURES LATE THIS MORNING AND THIS AFTERNOON. THIS WOULD RESULT IN A DEVELOPING CUMULUS FIELD...BUT NOT NEARLY AS EXPANSIVE AS SATURDAY. ALSO...THE TRAJECTORY OFF OF LAKE ERIE WOULD SUGGEST A FEW CLOUDS COULD REACH THE SOUTHERN POCONOS...BUT NOT ENOUGH TO APPRECIABLY CHANGE THE SKY COVER FORECAST. FURTHER SOUTH...WHERE CONVECTIVE TEMPERATURES ARE ABOVE 90 DEGREES...WOULD EXPECT LITTLE CUMULUS DEVELOPMENT. 1200 UTC SOUNDINGS SUGGEST MIXING FROM ABOUT 850 MB OR SO...AND YIELD HIGHS IN THE MID TO UPPER 70S FOR MOST PLACES. THIS IS IN LINE WITH CURRENT THINKING...AND NOT MUCH CHANGE NEEDED HERE. THE BEST SURFACE GRADIENT IS NORTH OF THE AREA THIS MORNING...AS HIGH PRESSURE SLIDES TO THE EAST. 1200 UTC SOUNDINGS AND ACARS SOUNDINGS SUGGEST THAT WINDS AROUND 30 KNOTS WILL BE AVAILABLE AT THE TOP OF THE INVERSION. THIS WOULD IMPLY GUSTS TO NEAR 25 MPH...BUT NOT SURE THIS MUCH MIXING WILL OCCUR. WILL CONTINUE TO MONITOR WINDS...AND MAY HAVE TO ACCOUNT FOR GUSTS IN THE LATE MORNING UPDATE. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... THIS FORECAST IS PRETTY BASIC WITH VERY DRY AIR FEATURED THROUGH AT LEAST MONDAY THEN A BRIEF SIGNIFICANT WARM UP TUESDAY INTO WEDNESDAY AS THE MID ATLANTIC STATES HIGH BECOMES ABSORBED INTO THE BERMUDA HIGH. A COOL FRONTAL PASSAGE ALOFT PROBABLY OCCURS BY MIDDAY WEDNESDAY WITH A NARROW BAND OF SCATTERED SHOWERS OR SPRINKLES POSSIBLE AHEAD OF IT BUT LOW PROBABILITIES AND NO SUBSTANTIAL RAINFALL CURRENTLY FORESEEN FOR AT LEAST THE NEXT 6 DAYS. TEMPERATURES ARE BLENDED NCEP 00Z/5 NAM/GFS GUIDANCE AND VERY CLOSE TO THAT WHICH WAS FORECAST YESTERDAY. POPS ARE 21Z/4 SREF THRU 12Z WED AND THEN ON WEDNESDAY THE NEW 00Z/5 MEX GUIDANCE POPS BLENDED WITH THE PREVIOUS KPHI 4PM SATURDAY 9/4 FCST. TONIGHT...CHILLY AS HIGH PRESSURE PERMITS DECOUPLING AGAIN AND GOOD SLEEPING WX. TEMPERATURES AS COOL OR PERHAPS 2-3 DEGS COOLER THAN THIS MORNINGS VALUES. MONDAY...STARTS WARMING UP BUT SUNNY. POSSIBLY A BAND OF MIDDLE DECK CLOUD INVADES THE SKY...ESP NW PTN OF THE FA IN THE AFTERNOON. AFTERNOON SEA BREEZES ON THE COAST. MONDAY NIGHT...FAIR AND NOT QUITE AS COOL BUT STILL QUITE NICE! PATCHY FOG FOR AN HR OR SO NEAR DAWN TUESDAY IF THE GRIDDED FCST TEMPS AND DEWS ARE ACCURATE...MAINLY IN NJ...DEL AND E MD AS LIGHT SLY SHALLOW SOUTHERLY FLOW MOISTURE CREEPS INTO THE PICTURE WITH A BIT OF RADIATIONAL COOLING AT NIGHT POSSIBLY YIELDING PATCHY 2F. TUESDAY...BECOMING VERY WARM IN THE AFTERNOON. POSSIBLE AFTERNOON SEA BREEZES ALONG THE COAST. WEDNESDAY...A MORNING BAND OF INSTABILITY ASSTD WITH COOL FRONTAL PASSAGE ALOFT MAY YIELD A SPRINKLE OR SHOWER BUT WIDESPREAD BENEFICIAL SHOWERS NOT FORESEEN IN THIS WESTERLY FLOW ILL TIMED CFP /ILL TIMED FOR HEAVIER CONVECTION POTENTIAL IN OUR AREA/. ATTM...KEPT THE FCST AS SHOWERS SINCE IT LOOKS LIKE MOSTLY A MORNING/ MIDDAY CFP WITH PROBABLY LESS THAN IDEAL INSTABILITY FOR THUNDER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. HIGH PRESSURE STRETCHED FROM THE UPPER OHIO VALLEY TO THE SOUTHERN MID ATLANTIC COAST WILL GRADUALLY SLIDE EASTWARD TONIGHT AND MONDAY. A RATHER DRY AIRMASS CONTINUES TO BE IN PLACE, HOWEVER WITH THE DAYTIME HEATING SOME STRATOCUMULUS/CUMULUS HAVE DEVELOPED BUT THE COVERAGE IS MUCH LESS THAN WHAT WAS OBSERVED YESTERDAY. WE CONTINUED TO PLACE THE GREATER COVERAGE /SCATTERED/ AT KABE AND KRDG INTO THIS EVENING, ALTHOUGH SATELLITE IMAGERY TRENDS INDICATE THAT THE EASTERN EDGE OF THE CLOUD MASS IS ERODING AS IT TRIES TO MOVE FATHER EASTWARD. THE PRESSURE GRADIENT IS MUCH WEAKER TODAY COMPARED TO YESTERDAY, ALTHOUGH THERE IS ENOUGH VERTICAL MIXING TO ALLOW SOME GUSTS TO NEAR 20 KNOTS THIS AFTERNOON. AT MOST OF THE TERMINALS, WE OPTED TO GO WITH A SLIGHTLY HIGHER SUSTAINED WIND INTO THIS EVENING WITH NO GUSTS INDICATED AS A DOWNWARD TREND IN THE OVERALL WESTERLY WINDS IS EXPECTED. ANY LINGERING CLOUDS WILL DISSIPATE THROUGH THE EVENING AND THE WINDS ARE EXPECTED TO GO LIGHT AND VARIABLE TO CALM AT ALL OUR TERMINALS OVERNIGHT. FOR MONDAY, HIGH PRESSURE SETTLES ACROSS OUR AREA BUT WILL ALSO BE GRADUALLY SHIFTING TO THE EAST. THIS WILL ALLOW A LIGHT AND VARIABLE WIND TO INCREASE TO NEAR 10 KNOTS AND BECOME SOUTHWESTERLY. IT IS FORECAST TO BE WARMER MONDAY AFTERNOON, AND WITH THE LIGHTER WINDS, A SEA BREEZE SHOULD DEVELOP AND GET TO KACY. LITTLE IN THE WAY OF CLOUDS ARE ANTICIPATED, THEREFORE VFR CONDITIONS ARE FORECAST TO PREVAIL. OUTLOOK... AS HIGH PRESSURE SLIDES TO OUR EAST MONDAY NIGHT AND TUESDAY, A SOUTH TO SOUTHWEST WIND WILL INCREASE TO 10 TO 15 KNOTS TUESDAY. A COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA DURING WEDNESDAY AND THERE IS SMALL CHANCE A FEW SHOWERS ACCOMPANY IT. OTHERWISE, A WIND SHIFT FROM THE SOUTHWEST TO THE NORTHWEST IS EXPECTED BEHIND THE FRONT. A NORTH TO NORTHWEST WIND IS THEN FORECAST FOR THURSDAY AND FRIDAY AS HIGH PRESSURE GRADUALLY ARRIVES. && .MARINE... HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA WATERS THROUGH TUESDAY AND SEAS AND WINDS REMAIN BELOW ADVISORY CRITERIA. THEREFORE, NO ADDITIONAL HEADLINES ARE EXPECTED THROUGH THE PERIOD. SEAS COULD INCREASE A BIT IN ADVANCE OF A COLD FRONT EXPECTED TO APPROACH AROUND MIDWEEK. AT THIS POINT GUIDANCE INDICATES CONDITIONS WILL REMAIN BELOW SMALL CRAFT CRITERIA WITH WARMER AIR OVER THE WARM WATERS. && .FIRE WEATHER... 1200 UTC SOUNDINGS AND ACARS SOUNDINGS FROM KPHL SHOW MIXING HEIGHTS BETWEEN 5500 AND 6000 FEET. WINDS TO NEAR 30 KNOTS WERE AVAILABLE AT THE TOP OF THE MIXED LAYER...AND WITH HEATING WOULD BE AVAILABLE FOR GUSTS. THE BEST GRADIENT THIS MORNING IS NORTH OF THE AREA...AND HIGH PRESSURE SLIDING EAST SHOULD KEEP THE SUSTAINED WINDS LESS THAN SATURDAY. THE DEPTH OF THE MIXED LAYER WOULD ALSO YIELD RELATIVE HUMIDITY VALUES NEAR 30 PERCENT THIS AFTERNOON. SINCE WE ARE CLOSE TO RED FLAG CRITERIA...HAVE ISSUED A SPECIAL WEATHER STATEMENT OUTLINING THE THREAT. SHOULD GUSTS HIGHER THAN 20 MPH MATERIALIZE LATER THIS MORNING...AN SHORT FUSED RED FLAG WARNING MAY BE NEEDED. AT THIS POINT...MUCH OF NEW JERSEY...SOUTHEAST PENNSYLVANIA... DELAWARE AND EASTERN MARYLAND WOULD HAVE THE GREATEST THREAT. && .RIP CURRENTS... LONG PERIOD SWELLS REMAIN ACROSS THE MID ATLANTIC OCEAN WATERS TODAY, PRODUCING AN ENHANCED RIP CURRENT RISK. WHILE THE SEAS HAVE DECREASED FROM THE LAST FEW DAYS, WAVES IN THE SURF ZONE TODAY WILL AVERAGE NEAR 3 FEET. AS A RESULT, THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING. THERE WERE REPORTS OF SEVERAL RESCUES CONDUCTED ON SATURDAY AT THE AREA BEACHES. SINCE WE ARE IN A HOLIDAY WEEKEND WITH LOTS OF PEOPLE AT THE COAST, WE OPTED TO ISSUE A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT TO HIGHLIGHT THE MODERATE RISK. THE CONDITIONS ARE ANTICIPATED TO IMPROVE FOR LABOR DAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM.../ AVIATION...GORSE MARINE...GORSE/NIERENBERG FIRE WEATHER...HAYES RIP CURRENTS...GORSE 000 FXUS61 KPHI 051314 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 914 AM EDT SUN SEP 5 2010 .SYNOPSIS... GENERALLY RAIN FREE WEATHER IS FEATURED INTO AT LEAST THE START OF THIS COMING WEEKEND AS LOW PRESSURE SYSTEMS MOVING INTO SOUTHEAST CANADA ARE THE PRIMARY INFLUENCE UPON OUR WEATHER. REFRESHINGLY COOL HIGH PRESSURE BUILDING EAST INTO THE MID ATLANTIC STATES TODAY BECOMES PART OF THE BERMUDA HIGH ON MONDAY PERMITTING A BRIEF WARM UP TUESDAY AND WEDNESDAY. AFTER A COLD FRONT CROSSES THE REGION WEDNESDAY...COOL CENTRAL CANADA HIGH PRESSURE FOLLOWS... EVENTUALLY SETTLING INTO THE MID ATLANTIC STATES BY NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NOT MUCH CHANGE FROM THE PREVIOUS FORECAST THIS MORNING. 1200 UTC SOUNDINGS SUGGEST THAT NORTHERN AREAS HAVE A BETTER CHANCE OF REACHING CONVECTIVE TEMPERATURES LATE THIS MORNING AND THIS AFTERNOON. THIS WOULD RESULT IN A DEVELOPING CUMULUS FIELD...BUT NOT NEARLY AS EXPANSIVE AS SATURDAY. ALSO...THE TRAJECTORY OFF OF LAKE ERIE WOULD SUGGEST A FEW CLOUDS COULD REACH THE SOUTHERN POCONOS...BUT NOT ENOUGH TO APPRECIABLY CHANGE THE SKY COVER FORECAST. FURTHER SOUTH...WHERE CONVECTIVE TEMPERATURES ARE ABOVE 90 DEGREES...WOULD EXPECT LITTLE CUMULUS DEVELOPMENT. 1200 UTC SOUNDINGS SUGGEST MIXING FROM ABOUT 850 MB OR SO...AND YIELD HIGHS IN THE MID TO UPPER 70S FOR MOST PLACES. THIS IS IN LINE WITH CURRENT THINKING...AND NOT MUCH CHANGE NEEDED HERE. THE BEST SURFACE GRADIENT IS NORTH OF THE AREA THIS MORNING...AS HIGH PRESSURE SLIDES TO THE EAST. 1200 UTC SOUNDINGS AND ACARS SOUNDINGS SUGGEST THAT WINDS AROUND 30 KNOTS WILL BE AVAILABLE AT THE TOP OF THE INVERSION. THIS WOULD IMPLY GUSTS TO NEAR 25 MPH...BUT NOT SURE THIS MUCH MIXING WILL OCCUR. WILL CONTINUE TO MONITOR WINDS...AND MAY HAVE TO ACCOUNT FOR GUSTS IN THE LATE MORNING UPDATE. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... THIS FORECAST IS PRETTY BASIC WITH VERY DRY AIR FEATURED THROUGH AT LEAST MONDAY THEN A BRIEF SIGNIFICANT WARM UP TUESDAY INTO WEDNESDAY AS THE MID ATLANTIC STATES HIGH BECOMES ABSORBED INTO THE BERMUDA HIGH. A COOL FRONTAL PASSAGE ALOFT PROBABLY OCCURS BY MIDDAY WEDNESDAY WITH A NARROW BAND OF SCATTERED SHOWERS OR SPRINKLES POSSIBLE AHEAD OF IT BUT LOW PROBABILITIES AND NO SUBSTANTIAL RAINFALL CURRENTLY FORESEEN FOR AT LEAST THE NEXT 6 DAYS. TEMPERATURES ARE BLENDED NCEP 00Z/5 NAM/GFS GUIDANCE AND VERY CLOSE TO THAT WHICH WAS FORECAST YESTERDAY. POPS ARE 21Z/4 SREF THRU 12Z WED AND THEN ON WEDNESDAY THE NEW 00Z/5 MEX GUIDANCE POPS BLENDED WITH THE PREVIOUS KPHI 4PM SATURDAY 9/4 FCST. TONIGHT...CHILLY AS HIGH PRESSURE PERMITS DECOUPLING AGAIN AND GOOD SLEEPING WX. TEMPERATURES AS COOL OR PERHAPS 2-3 DEGS COOLER THAN THIS MORNINGS VALUES. MONDAY...STARTS WARMING UP BUT SUNNY. POSSIBLY A BAND OF MIDDLE DECK CLOUD INVADES THE SKY...ESP NW PTN OF THE FA IN THE AFTERNOON. AFTERNOON SEA BREEZES ON THE COAST. MONDAY NIGHT...FAIR AND NOT QUITE AS COOL BUT STILL QUITE NICE! PATCHY FOG FOR AN HR OR SO NEAR DAWN TUESDAY IF THE GRIDDED FCST TEMPS AND DEWS ARE ACCURATE...MAINLY IN NJ...DEL AND E MD AS LIGHT SLY SHALLOW SOUTHERLY FLOW MOISTURE CREEPS INTO THE PICTURE WITH A BIT OF RADIATIONAL COOLING AT NIGHT POSSIBLY YIELDING PATCHY 2F. TUESDAY...BECOMING VERY WARM IN THE AFTERNOON. POSSIBLE AFTERNOON SEA BREEZES ALONG THE COAST. WEDNESDAY...A MORNING BAND OF INSTABILITY ASSTD WITH COOL FRONTAL PASSAGE ALOFT MAY YIELD A SPRINKLE OR SHOWER BUT WIDESPREAD BENEFICIAL SHOWERS NOT FORESEEN IN THIS WESTERLY FLOW ILL TIMED CFP /ILL TIMED FOR HEAVIER CONVECTION POTENTIAL IN OUR AREA/. ATTM...KEPT THE FCST AS SHOWERS SINCE IT LOOKS LIKE MOSTLY A MORNING/ MIDDAY CFP WITH PROBABLY LESS THAN IDEAL INSTABILITY FOR THUNDER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. HIGH PRESSURE BUILDING FROM THE SOUTHWEST IS ACCOMPANIED BY A RATHER DRY AIRMASS. THIS CAN BE SEEN BY LITTLE TO NO CLOUDS ACROSS THE AREA ON VISIBLE SATELLITE IMAGERY /AS OF 13Z/. AS SURFACE HEATING CONTINUES, WE SHOULD BE ABLE TO DEVELOP SOME CUMULUS ESPECIALLY FOR KABE AND KRDG BUT WITH NOT AS MUCH COVERAGE AS SEEN YESTERDAY. ANY CLOUDS ARE EXPECTED TO MELT AWAY DURING THE EVENING HOURS. A GENERAL WESTERLY WIND IS EXPECTED TODAY WITH SPEEDS INCREASING TO THE 10 TO 15 KNOT RANGE LATER THIS MORNING WITH GUSTS TO NEAR 20 KNOTS THROUGH SUNSET. WINDS WILL BECOME SOUTHWESTERLY OR EVEN VARIABLE OVERNIGHT WITH SPEEDS 5 KNOTS OR LESS. ON MONDAY, MORE OF A SOUTHERLY WIND WILL DEVELOP WITH SPEEDS AROUND 10 KNOTS. OUTLOOK... VFR CONDITIONS WILL PREVAIL AS HIGH PRESSURE REMAINS IN CONTROL THROUGH TUESDAY. A WEAK COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY AND COULD PRODUCE A FEW SHOWERS. THE COLD FRONT IS THEN EAST OF OUR AREA THURSDAY. && .MARINE... HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA WATERS THROUGH TUESDAY AND SEAS AND WINDS REMAIN BELOW ADVISORY CRITERIA. THEREFORE, NO ADDITIONAL HEADLINES ARE EXPECTED THROUGH THE PERIOD. SEAS COULD INCREASE A BIT IN ADVANCE OF A COLD FRONT EXPECTED TO APPROACH AROUND MIDWEEK. AT THIS POINT GUIDANCE INDICATES CONDITIONS WILL REMAIN BELOW SMALL CRAFT CRITERIA WITH WARMER AIR OVER THE WARM WATERS. && .FIRE WEATHER... 1200 UTC SOUNDINGS AND ACARS SOUNDINGS FROM KPHL SHOW MIXING HEIGHTS BETWEEN 5500 AND 6000 FEET. WINDS TO NEAR 30 KNOTS WERE AVAILABLE AT THE TOP OF THE MIXED LAYER...AND WITH HEATING WOULD BE AVAILABLE FOR GUSTS. THE BEST GRADIENT THIS MORNING IS NORTH OF THE AREA...AND HIGH PRESSURE SLIDING EAST SHOULD KEEP THE SUSTAINED WINDS LESS THAN SATURDAY. THE DEPTH OF THE MIXED LAYER WOULD ALSO YIELD RELATIVE HUMIDITY VALUES NEAR 30 PERCENT THIS AFTERNOON. SINCE WE ARE CLOSE TO RED FLAG CRITERIA...HAVE ISSUED A SPECIAL WEATHER STATEMENT OUTLINING THE THREAT. SHOULD GUSTS HIGHER THAN 20 MPH MATERIALIZE LATER THIS MORNING...AN SHORT FUSED RED FLAG WARNING MAY BE NEEDED. AT THIS POINT...MUCH OF NEW JERSEY...SOUTHEAST PENNSYLVANIA... DELAWARE AND EASTERN MARYLAND WOULD HAVE THE GREATEST THREAT. && .RIP CURRENTS... LONG PERIOD SWELLS REMAIN ACROSS THE MID ATLANTIC OCEAN WATERS TODAY, PRODUCING AN ENHANCED RIP CURRENT RISK. WHILE THE SEAS HAVE DECREASED FROM THE LAST FEW DAYS, WAVES IN THE SURF ZONE TODAY WILL AVERAGE NEAR 3 FEET. AS A RESULT, THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING. THERE WERE REPORTS OF SEVERAL RESCUES CONDUCTED ON SATURDAY AT THE AREA BEACHES. SINCE WE ARE IN A HOLIDAY WEEKEND WITH LOTS OF PEOPLE AT THE COAST, WE OPTED TO ISSUE A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT TO HIGHLIGHT THE MODERATE RISK. THE CONDITIONS ARE ANTICIPATED TO IMPROVE FOR LABOR DAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM.../ AVIATION...NIERENBERG/GORSE MARINE...NIERENBERG/GORSE FIRE WEATHER...HAYES RIP CURRENTS...GORSE 000 FXUS61 KPHI 050747 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 347 AM EDT SUN SEP 5 2010 .SYNOPSIS... GENERALLY RAIN FREE WEATHER IS FEATURED INTO AT LEAST THE START OF THIS COMING WEEKEND AS LOW PRESSURE SYSTEMS MOVING INTO SOUTHEAST CANADA ARE THE PRIMARY INFLUENCE UPON OUR WEATHER. REFRESHINGLY COOL HIGH PRESSURE BUILDING EAST INTO THE MID ATLANTIC STATES TODAY BECOMES PART OF THE BERMUDA HIGH ON MONDAY PERMITTING A BRIEF WARM UP TUESDAY AND WEDNESDAY. AFTER A COLD FRONT CROSSES THE REGION WEDNESDAY...COOL CENTRAL CANADA HIGH PRESSURE FOLLOWS... EVENTUALLY SETTLING INTO THE MID ATLANTIC STATES BY NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CHILLY IN THE COUNTRYSIDE EARLY THIS MORNING. TODAY...DIURNAL DRIVEN CU FIELDS MIDDAY/AFTERNOON BUT NOT AS WIDESPREAD AS YESTERDAY. GUSTY WEST WINDS LATE HIS MORNING AND AFTERNOON GENERALLY BELOW 18 KNOTS. QUITE A COMFORTABLE DAY! BLENDED 00Z/5 NCEP MOS GUIDANCE CHECKED AGAINST THE 00Z EC AND UK OP RUNS AND THEIR ASSTD FCST SFC TEMPS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... THIS FORECAST IS PRETTY BASIC WITH VERY DRY AIR FEATURED THROUGH AT LEAST MONDAY THEN A BRIEF SIGNIFICANT WARMUP TUESDAY INTO WEDNESDAY AS THE MID ATLANTIC STATES HIGH BECOMES ABSORBED INTO THE BERMUDA HIGH. A COOL FRONTAL PASSAGE ALOFT PROBABLY OCCURS BY MIDDAY WEDNESDAY WITH A NARROW BAND OF SCATTERED SHOWERS OR SPRINKLES POSSIBLE AHEAD OF IT BUT LOW PROBABILITIES AND NO SUBSTANTIAL RAINFALL CURRENTLY FORESEEN FOR AT LEAST THE NEXT 6 DAYS. TEMPERATURES ARE BLENDED NCEP 00Z/5 NAM/GFS GUIDANCE AND VERY CLOSE TO THAT WHICH WAS FORECAST YESTERDAY. POPS ARE 21Z/4 SREF THRU 12Z WED AND THEN ON WEDNESDAY THE NEW 00Z/5 MEX GUIDANCE POPS BLENDED WITH THE PREVIOUS KPHI 4PM SATURDAY 9/4 FCST. TONIGHT...CHILLY AS HIGH PRESSURE PERMITS DECOUPLING AGAIN AND GOOD SLEEPING WX. TEMPERATURES AS COOL OR PERHAPS 2-3 DEGS COOLER THAN THIS MORNINGS VALUES. MONDAY...STARTS WARMING UP BUT SUNNY. POSSIBLY A BAND OF MIDDLE DECK CLOUD INVADES THE SKY...ESP NW PTN OF THE FA IN THE AFTERNOON. AFTERNOON SEA BREEZES ON THE COAST. MONDAY NIGHT...FAIR AND NOT QUITE AS COOL BUT STILL QUITE NICE! PATCHY FOG FOR AN HR OR SO NEAR DAWN TUESDAY IF THE GRIDDED FCST TEMPS AND DEWS ARE ACCURATE...MAINLY IN NJ...DEL AND E MD AS LIGHT SLY SHALLOW SOUTHERLY FLOW MOISTURE CREEPS INTO THE PICTURE WITH A BIT OF RADIATIONAL COOLING AT NIGHT POSSIBLY YIELDING PATCHY 2F. TUESDAY...BECOMING VERY WARM IN THE AFTERNOON. POSSIBLE AFTERNOON SEA BREEZES ALONG THE COAST. WEDNESDAY...A MORNING BAND OF INSTABILITY ASSTD WITH COOL FRONTAL PASSAGE ALOFT MAY YIELD A SPRINKLE OR SHOWER BUT WIDESPREAD BENEFICIAL SHOWERS NOT FORESEEN IN THIS WESTERLY FLOW ILL TIMED CFP /ILL TIMED FOR HEAVIER CONVECTION POTENTIAL IN OUR AREA/. ATTM...KEPT THE FCST AS SHOWERS SINCE IT LOOKS LIKE MOSTLY A MORNING/ MIDDAY CFP WITH PROBABLY LESS THAN IDEAL INSTABILITY FOR THUNDER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LATEST SATELLITE IMAGERY SHOWED BASICALLY A CLEAR SKY OVER THE MID-ATLC REGION, AND WITH THE EXCEPTION OF SOME AFTN FAIR WX CU, EXPECT A MAINLY CLEAR SKY THRU THE PD. VFR CONDS WILL CONTINUE INTO MIDWEEK AS HIGH PRESSURE REMAINS OVER THE AREA. A GENL WLY WIND IS EXPECTED TODAY WITH SPEEDS INCREASING TO THE 10 TO 15 KT RANGE LATER THIS AM AND GUSTS TO ABOUT 20 KT THRU SUNSET. WINDS WILL BECOME SWLY OVERNIGHT WITH SPEEDS 5 KT OR LESS. ON MONDAY, MORE OF A SLY WIND WILL DEVELOP WITH SPEEDS AROUND 10 KT. OUTLOOK... VFR CONDITIONS WILL PREVAIL THROUGH THE OUTLOOK PERIOD AS HIGH PRESSURE REMAINS IN CONTROL THROUGH TUESDAY. A WEAK COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY AND COULD BRING A SHOWER AS IT PASSES. && .MARINE... HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA WATERS THROUGH TUESDAY AND SEAS AND WINDS HAVE BEGUN TO DIMINISH. OVER THE NRN WATERS, WINDS WERE STILL A BIT GUSTY EARLY THIS AM, BUT SEAS HAVE DROPPED CONSIDERABLY AND THE SCA WAS ALLOWED TO EXPIRE AT MIDNIGHT. NO ADDITIONAL MARINE FLAGS ARE EXPECTED THROUGH THE PD, WITH A RATHER TRANQUIL TIME IN STORE FOR THE WATERS. SEAS COULD INCREASE A BIT IN ADVANCE OF A CDFNT EXPECTED TO APPROACH AROUND MIDWEEK. AT THIS POINT GUID INDICATES CONDS WILL REMAIN BELOW SCA CRITERIA WITH WARMER AIR OVER THE WATERS. && .RIP CURRENTS... CONDITIONS OVERALL ARE EXPECTED TO IMPROVE TODAY AND EVEN MORE LABOR DAY AS THE SEAS AND WINDS CONTINUE TO DECREASE. HOWEVER...THE LATEST GUID STILL INDICATES A MODERATE RISK OF RIP CURRENTS TODAY. CONDS MAY IMPROVE A BIT DURG THE AFTN AS WINDS AND SEAS FURTHER SUBSIDE. && .FIRE WEATHER... MIN RH BELOW AT OR BELOW 30 PERCENT THIS AFTERNOON AND AGAIN MONDAY AFTERNOON. AFTERNOON WIND GUSTS MOSTLY BELOW 18 KNOTS AND NO FIRES REPORTED YESTERDAY...AS FAR AS I COULD DETERMINE FROM FIRE REPORTING RESOURCES...SO NO RED FLAG ISSUED ATTM. JUST ELEVATED RISK BUT NO STATEMENTS. IF WINDS END UP 2 OR 3 KNOTS STRONGER...ITS POSSIBLE A RED FLAG WOULD BE ISSUED IN THE LATE MORNING FORECAST UPDATE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM.../ AVIATION...NIERENBERG / MARINE...NIERENBERG / FIRE WEATHER... RIP CURRENTS... 000 FXUS61 KPHI 050635 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 235 AM EDT SUN SEP 5 2010 .SYNOPSIS... GENERALLY RAINFREE WEATHER IS FEATURED INTO AT LEAST THE START OF THIS COMING WEEKEND AS LOW PRESSURE SYSTEMS MOVING INTO SOUTHEAST CANADA GOVERN THE WEEKS WEATHER. REFRESHINGLY COOL HIGH PRESSURE BUILDING EAST INTO THE MID ATLANTIC STATES TODAY BECOMES PART OF THE BERMUDA HIGH ON MONDAY PERMITTING A BRIEF WARMER UP TUESDAY AND WEDNESDAY. A COLD FRONT WILL CROSS THE REGION WEDNESDAY WITH COOL CENTRAL CANADA HIGH PRESSURE EVENTUALLY SETTLING INTO THE MID ATLANTIC STATES TO BEGIN NEXT WEEKEND. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... CHILLY IN THE COUNTRYSIDE EARLY THIS MORNING. && .SHORT TERM /7 AM THIS MORNING THROUGH TUESDAY NIGHT/... THIS FORECAST IS PRETTY BASIC WITH VERY DRY AIR FEATURED TODAY AND MONDAY THEN A BRIEF SIGNIFICANT WARMUP TUESDAY INTO WEDNESDAY AS THE MID ATLANTIC STATES HIGH JOINS THE BERMUDA HIGH. THE COOL FRONTAL PASSAGE ALOFT PROBABLY OCCURS BY MIDDAY WEDNESDAY WITH NARROW BAND OF SCATTERED SHOWERS OR SPRINKLES POSSIBLE AHEAD OF IT BUT LOW PROBABILITIES AND NO SUBSTANTIAL CURRENTLY FORESEEN. TEMPERATURES ARE BLENDED NCEP 00Z/5 NAM/GFS GUIDANCE AND VERY CLOSE TO THAT WHICH WAS FORECAST YESTERDAY. TODAY...DIURNAL DRIVEN CU FIELDS TODAY BUT NOT AS NOTICEABLE AS YESTERDAY. GUSTY WEST WINDS GENERALLY BELOW 18 KNOTS. TONIGHT...CHILLY AS HIGH PRESSURE PERMITS DECOUPLING AGAIN AND JUST WONDERFUL SLEEPING WX. MONDAY...STARTS WARMING UP BUT SUNNY. POSSIBLY A BAND OF MIDDLE DECK CLOUD INVADES THE SKY...ESP NW PTN OF THE FA IN THE AFTERNOON. AFTERNOON SEA BREEZES ON THE COAST. MONDAY NIGHT...FAIR BUT NOT AS COOL BUT STILL QUITE NICE! TUESDAY...BECOMING VERY WARM IN THE AFTERNOON. POSSIBLE AFTERNOON SEA BREEZES ALONG THE COAST. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. WITH HIGHS IN THE MID AND UPPER 80S...AND MAYBE NEAR 90...IT WAS DECIDED TO CARRY A MENTION OF THUNDER FOR WEDNESDAY AFTERNOON AND INTO THE EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE CUMULUS FIELD WAS DISSIPATING AS DIURNAL AND TERRAIN EFFECTS WERE LESSENING EARLY THIS EVENING. ALSO...WIND GUSTS WERE DECREASING AS THE GRADIENT WEAKENED AND THE BOUNDARY LAYER WAS IN THE PROCESS OF PARTIALLY DECOUPLING. SO...AFTER STARTING WITH A ONE OR TWO HOUR PERIOD OF TRANSITION WITH LOWER SUSTAINED WINDS AND WIND GUSTS AND A FEW ALTOCUMULUS...WEST WINDS LESS THAN 8 KNOTS AND CLEAR SKIES ARE FORECAST FOR TONIGHT. FOR SUNDAY, FINE VFR FLYING CONDITIONS WILL RESULT AS HIGH PRESSURE TO OUR WEST BUILDS CLOSER AND ALLOWS THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE...ALTHOUGH SPEEDS WILL BE LESS THAN THEY WERE SATURDAY. OVERALL 10 TO 15 KNOTS WAS FORECAST FOR THE RANGE...BUT SOME GUSTS WERE INCLUDED UP TO 18 OR 20 KNOTS STARTING ABOUT MID MORNING FOR THE MORE GUST-PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT OCCURRED SATURDAY AS THE AIRMASS WARMS A LITTLE BIT...THEREFORE ONLY FEW TO SCATTERED CUMULUS WERE CARRIED. OUTLOOK... VFR CONDITIONS WILL PREVAIL THROUGH THE OUTLOOK PERIOD. HIGH PRESSURE WILL SETTLE OVER OUR AREA LATE SUNDAY AND CONTINUE MONDAY BEFORE MOVING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF AN APPROACHING COLD FRONT, HOWEVER THIS COLD FRONT LOOKS TO MOVE INTO OUR AREA ABOUT WEDNESDAY...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... WIND GUSTS WERE BELOW 20 KNOTS MOST EVERYWHERE AT 00Z...BUT SEAS WERE STILL ELEVATED OVER OUR NORTHERN WATERS. SO...THE SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT UNTIL MIDNIGHT TONIGHT /04Z/...AND THE MIDNIGHT SHIFT CAN MAKE A DETERMINATION AS TO WHETHER IT NEEDS TO BE EXTENDED THERE OR NOT. OTHERWISE CONDITIONS ON THE SOUTHERN COASTAL WATERS AND DELAWARE BAY WILL BE SUB-ADVISORY FROM HERE ON OUT. HIGH PRESSURE WILL BUILD GRADUALLY INTO OUR AREA FROM THE WEST SUNDAY AND MONDAY. THE OFFSHORE FLOW WILL BE IN THE 10 TO 15 KNOT RANGE SUNDAY BUT NOT AS GUSTY AS SATURDAY AS THE PRESSURE GRADIENT CONTINUES TO SHIFT NORTH AND OUT OF OUR AREA. HIGH PRESSURE WILL SHIFT TO OUR EAST TUESDAY WITH A RETURN FLOW BECOMING ESTABLISHED. AS THE FLOW IS LIGHTER MONDAY, SEA/BAY BREEZE CIRCULATIONS MAY OCCUR. THE SOUTHERLY FLOW WELL AHEAD OF AN ADVANCING COLD FRONT TUESDAY MAY ALLOW SOME INCREASE IN SPEEDS...BUT AT THIS TIME WINDS AND SEAS APPEAR TO BE BELOW ADVISORY CRITERIA GIVEN A WARMER AIRMASS IN PLACE. THE COLD FRONT IS FORECAST TO MOVE INTO OUR AREA LATE WEDNESDAY OR WEDNESDAY EVENING...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT LATER WEDNESDAY AND INTO WEDNESDAY EVENING. && .FIRE WEATHER... MIN RH BELOW AT OR BELOW 30 PERCENT THIS AFTERNOON AND AGAIN MONDAY AFTERNOON. AFTERNOON WIND GUSTS MOSTLY BELOW 18 KNOTS AND NO FIRES REPORTED YESTERDAY AS FAR AS I CAN TELL...SO NO RED FLAG. JUST ELEVATED RISK BUT NO STATEMENTS. && .RIP CURRENTS... CONDITIONS OVERALL ARE EXPECTED TO IMPROVE SUNDAY AND EVEN MORE LABOR DAY AS THE SEAS AND WINDS LOWER. HOWEVER...THE RIP CURRENT RISK MAY AGAIN BE MODERATE SUNDAY...BUT THIS WILL BE LEFT FOR THE MIDNIGHT SHIFT TO DETERMINE AS WE WILL NOT LOCK THEM INTO A FORECAST YET. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG/HAYES 235 NEAR TERM...DRAG 235 SHORT TERM...DRAG 235 LONG TERM.../ AVIATION.../ MARINE.../ FIRE WEATHER...235 RIP CURRENTS... 000 FXUS61 KPHI 050302 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1102 PM EDT SAT SEP 4 2010 .SYNOPSIS... HIGH PRESSURE OVER MISSOURI THIS EVENING WILL REACHING THE MID ATLANTIC COAST SUNDAY NIGHT AND MONDAY. THE RETURN FLOW AROUND THE HIGH WILL BRING WARMER AND MORE HUMID CONDITIONS FOR THE EARLY PART OF THE UPCOMING WEEK. A COLD FRONT WILL CROSS THE REGION WEDNESDAY EVENING. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH FROM ONTARIO FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 7 AM SUNDAY MORNING/... 1055 PM CHECK: DRY AIR WILL CONTINUE TO BE DRAWN INTO OUR REGION OVERNIGHT. THE FEW CLOUDS AND THE WIND WILL REMAIN ON THE DECREASE. IT CONTINUES TO APPEARS AS THOUGH TEMPERATURES WILL DROP INTO THE UPPER 40S AND 50S BY DAYBREAK. && .SHORT TERM /7 AM SUNDAY MORNING THROUGH TUESDAY/... WITH THE REGION IN CYCLONIC FLOW IN THE MID LEVELS SUNDAY...WOULD EXPECT CUMULUS TO DEVELOP ONCE AGAIN AS CONVECTIVE TEMPERATURES SHOULD BE WITHIN REACH. WHILE THERE WILL BE SOME GRADIENT OVER THE REGION...ESPECIALLY IN THE MORNING...WOULD EXPECT WINDS OVERALL TO BE LIGHT THAN THIS AFTERNOON. 850 MB TEMPERATURES SUGGEST TEMPERATURES NEAR OR JUST BELOW HIGHS REACHED TODAY. LEANED TOWARD THE COOLER GFS FOR THIS REASON FOR HIGHS. THE SURFACE HIGH WILL REACH THE MID ATLANTIC COAST SUNDAY NIGHT... WITH CYCLONIC FLOW IN PLACE IN THE MID LEVELS. THE GRADIENT SHOULD DROP OFF MORE QUICKLY SUNDAY EVENING. THIS AND CLEAR SKIES SHOULD BE MORE CONDUCIVE TO A GOOD RADIATIONAL COOLING NIGHT...AND FOR THIS REASON LEANED TOWARD THE COOLER GFS MOS NUMBERS AWAY FROM URBAN AREAS. THE RADIATIONAL COOLING SHOULD ALLOW VALLEY FOG TO FORM EARLY MONDAY MORNING...DESPITE THE RELATIVELY LOW DEW POINTS...AND THIS WILL BE RETAINED IN THE FORECAST. THE RETURN FLOW AROUND THE SURFACE HIGH OFF THE MID ATLANTIC COAST WILL START BRINGING WARMER AND MORE HUMID AIR NORTHWARD. IN THE MID LEVELS...THE FLOW WILL BECOME MORE ZONAL. THE COMBINATION SHOULD RESULT IN SOME CUMULUS DEVELOPMENT...BUT PROBABLY LESS THAN MONDAY. 850 MB TEMPERATURES LOOK TO BE ABOUT 2 DEGREES CELSIUS WARMER MONDAY THAN SUNDAY. WITH THIS IN MIND...LEANED TOWARD THE WARMER GFS MOS NUMBERS FOR HIGHS. THE GRADIENT SHOULD BE LIGHT ENOUGH TO ALLOW SEA/BAY BREEZE CIRCULATIONS TO DEVELOP IN THE AFTERNOON. THE 1200 UTC GFS IS MORE AGGRESSIVE WITH THE RETURN OF THE LOW LEVEL MOISTURE INTO THE FORECAST AREA MONDAY AFTERNOON. HIGHER PRECIPITABLE WATER VALUES...AND DECENT MID LEVEL LAPSE RATES...WOULD SUGGEST MARGINAL INSTABILITY FROM NORTHEAST MARYLAND THROUGH THE LEHIGH VALLEY. THE 1200 UTC NAM IS LESS BULLISH...AND AT THIS POINT WOULD BE INCLINED TO KEEP THE FORECAST DRY. FOR MONDAY NIGHT AND TUESDAY...MID LEVEL RIDGING REASSERTS ITSELF FROM THE CAROLINA. THIS WILL ALLOW EVEN WARM AIR TO MOVE NORTH INTO THE FORECAST AREA. HIGHER DEW POINTS MAY LEAD TO MARGINAL INSTABILITY FOR A GREATER PORTION OF THE FORECAST AREA. HOWEVER... WITH NO FOCUS IN PLACE...WILL OPT TO KEEP TUESDAY DRY AS WELL. 850 MB TEMPERATURES WARM BY ANOTHER 4 DEGREES FOR TUESDAY. THIS MAY ALLOW SOME AREAS TO REACH 90 DEGREES TUESDAY AFTERNOON. THIS WOULD BE A BIT ABOVE THE MOS GUIDANCE FOR TUESDAY. WITH THE AIRMASS MOISTENING...THE EXTRA HEAT MAY GOING INTO WARMING THE MOISTURE IN THE AIR AND NOT THE AIR ITSELF. WILL KEEP MOST HIGH TEMPERATURES JUST BELOW THE 90 DEGREE MARK. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. WITH HIGHS IN THE MID AND UPPER 80S...AND MAYBE NEAR 90...IT WAS DECIDED TO CARRY A MENTION OF THUNDER FOR WEDNESDAY AFTERNOON AND INTO THE EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE CUMULUS FIELD WAS DISSIPATING AS DIURNAL AND TERRAIN EFFECTS WERE LESSENING EARLY THIS EVENING. ALSO...WIND GUSTS WERE DECREASING AS THE GRADIENT WEAKENED AND THE BOUNDARY LAYER WAS IN THE PROCESS OF PARTIALLY DECOUPLING. SO...AFTER STARTING WITH A ONE OR TWO HOUR PERIOD OF TRANSITION WITH LOWER SUSTAINED WINDS AND WIND GUSTS AND A FEW ALTOCUMULUS...WEST WINDS LESS THAN 8 KNOTS AND CLEAR SKIES ARE FORECAST FOR TONIGHT. FOR SUNDAY, FINE VFR FLYING CONDITIONS WILL RESULT AS HIGH PRESSURE TO OUR WEST BUILDS CLOSER AND ALLOWS THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE...ALTHOUGH SPEEDS WILL BE LESS THAN THEY WERE SATURDAY. OVERALL 10 TO 15 KNOTS WAS FORECAST FOR THE RANGE...BUT SOME GUSTS WERE INCLUDED UP TO 18 OR 20 KNOTS STARTING ABOUT MID MORNING FOR THE MORE GUST-PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT OCCURRED SATURDAY AS THE AIRMASS WARMS A LITTLE BIT...THEREFORE ONLY FEW TO SCATTERED CUMULUS WERE CARRIED. OUTLOOK... VFR CONDITIONS WILL PREVAIL THROUGH THE OUTLOOK PERIOD. HIGH PRESSURE WILL SETTLE OVER OUR AREA LATE SUNDAY AND CONTINUE MONDAY BEFORE MOVING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF AN APPROACHING COLD FRONT, HOWEVER THIS COLD FRONT LOOKS TO MOVE INTO OUR AREA ABOUT WEDNESDAY...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... WIND GUSTS WERE BELOW 20 KNOTS MOST EVERYWHERE AT 00Z...BUT SEAS WERE STILL ELEVATED OVER OUR NORTHERN WATERS. SO...THE SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT UNTIL MIDNIGHT TONIGHT /04Z/...AND THE MIDNIGHT SHIFT CAN MAKE A DETERMINATION AS TO WHETHER IT NEEDS TO BE EXTENDED THERE OR NOT. OTHERWISE CONDITIONS ON THE SOUTHERN COASTAL WATERS AND DELAWARE BAY WILL BE SUB-ADVISORY FROM HERE ON OUT. HIGH PRESSURE WILL BUILD GRADUALLY INTO OUR AREA FROM THE WEST SUNDAY AND MONDAY. THE OFFSHORE FLOW WILL BE IN THE 10 TO 15 KNOT RANGE SUNDAY BUT NOT AS GUSTY AS SATURDAY AS THE PRESSURE GRADIENT CONTINUES TO SHIFT NORTH AND OUT OF OUR AREA. HIGH PRESSURE WILL SHIFT TO OUR EAST TUESDAY WITH A RETURN FLOW BECOMING ESTABLISHED. AS THE FLOW IS LIGHTER MONDAY, SEA/BAY BREEZE CIRCULATIONS MAY OCCUR. THE SOUTHERLY FLOW WELL AHEAD OF AN ADVANCING COLD FRONT TUESDAY MAY ALLOW SOME INCREASE IN SPEEDS...BUT AT THIS TIME WINDS AND SEAS APPEAR TO BE BELOW ADVISORY CRITERIA GIVEN A WARMER AIRMASS IN PLACE. THE COLD FRONT IS FORECAST TO MOVE INTO OUR AREA LATE WEDNESDAY OR WEDNESDAY EVENING...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT LATER WEDNESDAY AND INTO WEDNESDAY EVENING. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES WILL BE NEAR 30 PERCENT FOR A LARGE PORTION OF THE AREA SUNDAY AFTERNOON...BUT HIGH TEMPERATURES A FEW DEGREES LOWER THAN TODAY MAY KEEP THESE VALUES HIGHER. THE GRADIENT DOES NOT APPEAR TO SUPPORT WIND GUSTS ABOVE 18 KNOTS OVER MUCH OF THE AREA. ELEVATED FIRE DANGER RISK BUT NOT WATCHABLE. CHECKED ACTIVE FIREMAPS TODAY AND COULD NOT FIND ANY SIGNIFICANT FIRES IN OUR CWA. SINCE APPARENT DANGER DIDNT SEEM TO BE A SIGNIFICANT PROBLEM ON THE 4TH... EXPECT A LITTLE LESS RISK ON SUNDAY DUE TO SOMEWHAT LOWER WIND SPEEDS. THIS CAN BE REVISITED SUNDAY...IF WINDS ARE STRONGER THAN FORECAST OR IF IT APPEARS AS THOUGH RELATIVE HUMIDITY VALUES WILL DROP BELOW 30 PERCENT. && .RIP CURRENTS... CONDITIONS OVERALL ARE EXPECTED TO IMPROVE SUNDAY AND EVEN MORE LABOR DAY AS THE SEAS AND WINDS LOWER. HOWEVER...THE RIP CURRENT RISK MAY AGAIN BE MODERATE SUNDAY...BUT THIS WILL BE LEFT FOR THE MIDNIGHT SHIFT TO DETERMINE AS WE WILL NOT LOCK THEM INTO A FORECAST YET. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450-451. && $$ SYNOPSIS...HAYES NEAR TERM...DRAG/IOVINO 1101 SHORT TERM...HAYES LONG TERM.../ AVIATION.../ MARINE.../ FIRE WEATHER...1101P RIP CURRENTS... 000 FXUS61 KPHI 050012 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 812 PM EDT SAT SEP 4 2010 .SYNOPSIS... HIGH PRESSURE OVER MISSOURI THIS EVENING WILL BUILD EAST...REACHING THE MID ATLANTIC COAST SUNDAY NIGHT AND MONDAY. THE RETURN FLOW AROUND THE HIGH WILL BRING WARMER AND MORE HUMID CONDITIONS FOR THE EARLY PART OF THE UPCOMING WEEK. A COLD FRONT WILL APPROACH THE REGION WEDNESDAY...THEN CROSS THE REGION WEDNESDAY EVENING. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH FROM ONTARIO FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AT 800 PM, THE CUMULUS OVER OUR REGION WAS CONTINUING TO DISSIPATE AND THE WIND WAS DIMINISHING SLOWLY. TEMPERATURES WERE MAINLY IN THE 60S AND LOWER 70S, WITH DEW POINT READINGS IN THE 40S. DRY AIR WILL CONTINUE TO BE DRAWN INTO OUR REGION OVERNIGHT. THE FEW CLOUDS AND THE WIND WILL REMAIN ON THE DECREASE. IT CONTINUES TO APPEARS AS THOUGH TEMPERATURES WILL DROP INTO THE UPPER 40S AND 50S BY DAYBREAK. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... WITH THE REGION IN CYCLONIC FLOW IN THE MID LEVELS SUNDAY...WOULD EXPECT CUMULUS TO DEVELOP ONCE AGAIN AS CONVECTIVE TEMPERATURES SHOULD BE WITHIN REACH. WHILE THERE WILL BE SOME GRADIENT OVER THE REGION...ESPECIALLY IN THE MORNING...WOULD EXPECT WINDS OVERALL TO BE LIGHT THAN THIS AFTERNOON. 850 MB TEMPERATURES SUGGEST TEMPERATURES NEAR OR JUST BELOW HIGHS REACHED TODAY. LEANED TOWARD THE COOLER GFS FOR THIS REASON FOR HIGHS. THE SURFACE HIGH WILL REACH THE MID ATLANTIC COAST SUNDAY NIGHT... WITH CYCLONIC FLOW IN PLACE IN THE MID LEVELS. THE GRADIENT SHOULD DROP OFF MORE QUICKLY SUNDAY EVENING. THIS AND CLEAR SKIES SHOULD BE MORE CONDUCIVE TO A GOOD RADIATIONAL COOLING NIGHT...AND FOR THIS REASON LEANED TOWARD THE COOLER GFS MOS NUMBERS AWAY FROM URBAN AREAS. THE RADIATIONAL COOLING SHOULD ALLOW VALLEY FOG TO FORM EARLY MONDAY MORNING...DESPITE THE RELATIVELY LOW DEW POINTS...AND THIS WILL BE RETAINED IN THE FORECAST. THE RETURN FLOW AROUND THE SURFACE HIGH OFF THE MID ATLANTIC COAST WILL START BRINGING WARMER AND MORE HUMID AIR NORTHWARD. IN THE MID LEVELS...THE FLOW WILL BECOME MORE ZONAL. THE COMBINATION SHOULD RESULT IN SOME CUMULUS DEVELOPMENT...BUT PROBABLY LESS THAN MONDAY. 850 MB TEMPERATURES LOOK TO BE ABOUT 2 DEGREES CELSIUS WARMER MONDAY THAN SUNDAY. WITH THIS IN MIND...LEANED TOWARD THE WARMER GFS MOS NUMBERS FOR HIGHS. THE GRADIENT SHOULD BE LIGHT ENOUGH TO ALLOW SEA/BAY BREEZE CIRCULATIONS TO DEVELOP IN THE AFTERNOON. THE 1200 UTC GFS IS MORE AGGRESSIVE WITH THE RETURN OF THE LOW LEVEL MOISTURE INTO THE FORECAST AREA MONDAY AFTERNOON. HIGHER PRECIPITABLE WATER VALUES...AND DECENT MID LEVEL LAPSE RATES...WOULD SUGGEST MARGINAL INSTABILITY FROM NORTHEAST MARYLAND THROUGH THE LEHIGH VALLEY. THE 1200 UTC NAM IS LESS BULLISH...AND AT THIS POINT WOULD BE INCLINED TO KEEP THE FORECAST DRY. FOR MONDAY NIGHT AND TUESDAY...MID LEVEL RIDGING REASSERTS ITSELF FROM THE CAROLINA. THIS WILL ALLOW EVEN WARM AIR TO MOVE NORTH INTO THE FORECAST AREA. HIGHER DEW POINTS MAY LEAD TO MARGINAL INSTABILITY FOR A GREATER PORTION OF THE FORECAST AREA. HOWEVER... WITH NO FOCUS IN PLACE...WILL OPT TO KEEP TUESDAY DRY AS WELL. 850 MB TEMPERATURES WARM BY ANOTHER 4 DEGREES FOR TUESDAY. THIS MAY ALLOW SOME AREAS TO REACH 90 DEGREES TUESDAY AFTERNOON. THIS WOULD BE A BIT ABOVE THE MOS GUIDANCE FOR TUESDAY. WITH THE AIRMASS MOISTENING...THE EXTRA HEAT MAY GOING INTO WARMING THE MOISTURE IN THE AIR AND NOT THE AIR ITSELF. WILL KEEP MOST HIGH TEMPERATURES JUST BELOW THE 90 DEGREE MARK. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. WITH HIGHS IN THE MID AND UPPER 80S...AND MAYBE NEAR 90...IT WAS DECIDED TO CARRY A MENTION OF THUNDER FOR WEDNESDAY AFTERNOON AND INTO THE EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL- LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE CUMULUS FIELD WAS DISSIPATING AS DIURNAL AND TERRAIN EFFECTS WERE LESSENING EARLY THIS EVENING. ALSO...WIND GUSTS WERE DECREASING AS THE GRADIENT WEAKENED AND THE BOUNDARY LAYER WAS IN THE PROCESS OF PARTIALLY DECOUPLING. SO...AFTER STARTING WITH A ONE OR TWO HOUR PERIOD OF TRANSITION WITH LOWER SUSTAINED WINDS AND WIND GUSTS AND A FEW ALTOCUMULUS...WEST WINDS LESS THAN 8 KNOTS AND CLEAR SKIES ARE FORECAST FOR TONIGHT. FOR SUNDAY, FINE VFR FLYING CONDITIONS WILL RESULT AS HIGH PRESSURE TO OUR WEST BUILDS CLOSER AND ALLOWS THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE...ALTHOUGH SPEEDS WILL BE LESS THAN THEY WERE SATURDAY. OVERALL 10 TO 15 KNOTS WAS FORECAST FOR THE RANGE...BUT SOME GUSTS WERE INCLUDED UP TO 18 OR 20 KNOTS STARTING ABOUT MID MORNING FOR THE MORE GUST-PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT OCCURRED SATURDAY AS THE AIRMASS WARMS A LITTLE BIT...THEREFORE ONLY FEW TO SCATTERED CUMULUS WERE CARRIED. OUTLOOK... VFR CONDITIONS WILL PREVAIL THROUGH THE OUTLOOK PERIOD. HIGH PRESSURE WILL SETTLE OVER OUR AREA LATE SUNDAY AND CONTINUE MONDAY BEFORE MOVING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF AN APPROACHING COLD FRONT, HOWEVER THIS COLD FRONT LOOKS TO MOVE INTO OUR AREA ABOUT WEDNESDAY...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... WIND GUSTS WERE BELOW 20 KNOTS MOST EVERYWHERE AT 00Z...BUT SEAS WERE STILL ELEVATED OVER OUR NORTHERN WATERS. SO...THE SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT UNTIL MIDNIGHT TONIGHT /04Z/...AND THE MIDNIGHT SHIFT CAN MAKE A DETERMINATION AS TO WHETHER IT NEEDS TO BE EXTENDED THERE OR NOT. OTHERWISE CONDITIONS ON THE SOUTHERN COASTAL WATERS AND DELAWARE BAY WILL BE SUB-ADVISORY FROM HERE ON OUT. HIGH PRESSURE WILL BUILD GRADUALLY INTO OUR AREA FROM THE WEST SUNDAY AND MONDAY. THE OFFSHORE FLOW WILL BE IN THE 10 TO 15 KNOT RANGE SUNDAY BUT NOT AS GUSTY AS SATURDAY AS THE PRESSURE GRADIENT CONTINUES TO SHIFT NORTH AND OUT OF OUR AREA. HIGH PRESSURE WILL SHIFT TO OUR EAST TUESDAY WITH A RETURN FLOW BECOMING ESTABLISHED. AS THE FLOW IS LIGHTER MONDAY, SEA/BAY BREEZE CIRCULATIONS MAY OCCUR. THE SOUTHERLY FLOW WELL AHEAD OF AN ADVANCING COLD FRONT TUESDAY MAY ALLOW SOME INCREASE IN SPEEDS...BUT AT THIS TIME WINDS AND SEAS APPEAR TO BE BELOW ADVISORY CRITERIA GIVEN A WARMER AIRMASS IN PLACE. THE COLD FRONT IS FORECAST TO MOVE INTO OUR AREA LATE WEDNESDAY OR WEDNESDAY EVENING...THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT LATER WEDNESDAY AND INTO WEDNESDAY EVENING. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES WILL BE NEAR 30 PERCENT FOR A LARGE PORTION OF THE AREA SUNDAY AFTERNOON...BUT HIGH TEMPERATURES A FEW DEGREES LOWER THAN TODAY MAY KEEP THESE VALUES HIGHER. THE GRADIENT DOES NOT APPEAR TO SUPPORT WIND GUSTS ABOVE 20 KNOTS OVER MUCH OF THE AREA. WILL HOLD OFF ON A FIRE WEATHER WATCH FOR SUNDAY. THIS CAN BE REVISITED SUNDAY...IF WINDS ARE STRONGER THAN FORECAST OR IF IT APPEARS AS THOUGH RELATIVE HUMIDITY VALUES WILL DROP BELOW 30 PERCENT. && .RIP CURRENTS... CONDITIONS OVERALL ARE EXPECTED TO IMPROVE SUNDAY AND EVEN MORE LABOR DAY AS THE SEAS AND WINDS LOWER. HOWEVER...THE RIP CURRENT RISK MAY AGAIN BE MODERATE SUNDAY...BUT THIS WILL BE LEFT FOR THE MIDNIGHT SHIFT TO DETERMINE AS WE WILL NOT LOCK THEM INTO A FORECAST YET. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450-451. && $$ SYNOPSIS...HAYES NEAR TERM...IOVINO SHORT TERM...HAYES FIRE WEATHER...HAYES 000 FXUS61 KPHI 042110 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 510 PM EDT SAT SEP 4 2010 .SYNOPSIS... HIGH PRESSURE OVER THE MIDWEST WILL BUILD EAST...REACHING THE MID ATLANTIC COAST SUNDAY NIGHT AND MONDAY. THE RETURN FLOW AROUND THE HIGH WILL BRING WARMER AND MORE HUMID CONDITIONS FOR THE EARLY PART OF THE UPCOMING WEEK. A COLD FRONT WILL APPROACH THE REGION WEDNESDAY...THEN CROSS THE REGION WEDNESDAY EVENING. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH FROM ONTARIO FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE MID LEVEL LONG WAVE THROUGH WILL CROSS THE REGION THIS EVENING. THERE MAY BE ENOUGH INSTABILITY FOR A FEW SPRINKLES ACROSS THE HIGHER TERRAIN THIS EVENING. OTHERWISE... WITH THE LOSS OF DAYTIME HEATING...THE CUMULUS AND STRATOCUMULUS SHOULD MELT AWAY THIS EVENING. THIS MAY TAKE LONGER ACROSS THE NORTH WHERE CLOUDS FROM THE GREAT LAKES MAY CONTINUE TO STREAM EAST. THE BEST GRADIENT WILL REMAIN OVER THE FORECAST AREA THROUGH THE EVENING HOURS. FOR MOST PLACES...THE GUSTINESS SHOULD CEASE...BUT WINDS MAY NOT BECOME LIGHT UNTIL LATER THIS EVENING. WITH DEW POINTS AS LOW AS THEY ARE THIS EVENING...LIGHT WINDS MAY ALLOW FOR RADIATIONAL COOLING PROTECTED SPOTS. WILL LEAN TOWARD THE COOLER GFS MOS FOR LOWS...BUT NOT MUCH BELOW THIS AS IT WILL BE THE FIRST NIGHT IN THIS AIRMASS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... WITH THE REGION IN CYCLONIC FLOW IN THE MID LEVELS SUNDAY...WOULD EXPECT CUMULUS TO DEVELOP ONCE AGAIN AS CONVECTIVE TEMPERATURES SHOULD BE WITHIN REACH. WHILE THERE WILL BE SOME GRADIENT OVER THE REGION...ESPECIALLY IN THE MORNING...WOULD EXPECT WINDS OVERALL TO BE LIGHT THAN THIS AFTERNOON. 850 MB TEMPERATURES SUGGEST TEMPERATURES NEAR OR JUST BELOW HIGHS REACHED TODAY. LEANED TOWARD THE COOLER GFS FOR THIS REASON FOR HIGHS. THE SURFACE HIGH WILL REACH THE MID ATLANTIC COAST SUNDAY NIGHT... WITH CYCLONIC FLOW IN PLACE IN THE MID LEVELS. THE GRADIENT SHOULD DROP OFF MORE QUICKLY SUNDAY EVENING. THIS AND CLEAR SKIES SHOULD BE MORE CONDUCIVE TO A GOOD RADIATIONAL COOLING NIGHT...AND FOR THIS REASON LEANED TOWARD THE COOLER GFS MOS NUMBERS AWAY FROM URBAN AREAS. THE RADIATIONAL COOLING SHOULD ALLOW VALLEY FOG TO FORM EARLY MONDAY MORNING...DESPITE THE RELATIVELY LOW DEW POINTS...AND THIS WILL BE RETAINED IN THE FORECAST. THE RETURN FLOW AROUND THE SURFACE HIGH OFF THE MID ATLANTIC COAST WILL START BRINGING WARMER AND MORE HUMID AIR NORTHWARD. IN THE MID LEVELS...THE FLOW WILL BECOME MORE ZONAL. THE COMBINATION SHOULD RESULT IN SOME CUMULUS DEVELOPMENT...BUT PROBABLY LESS THAN MONDAY. 850 MB TEMPERATURES LOOK TO BE ABOUT 2 DEGREES CELSIUS WARMER MONDAY THAN SUNDAY. WITH THIS IN MIND...LEANED TOWARD THE WARMER GFS MOS NUMBERS FOR HIGHS. THE GRADIENT SHOULD BE LIGHT ENOUGH TO ALLOW SEA/BAY BREEZE CIRCULATIONS TO DEVELOP IN THE AFTERNOON. THE 1200 UTC GFS IS MORE AGGRESSIVE WITH THE RETURN OF THE LOW LEVEL MOISTURE INTO THE FORECAST AREA MONDAY AFTERNOON. HIGHER PRECIPITABLE WATER VALUES...AND DECENT MID LEVEL LAPSE RATES...WOULD SUGGEST MARGINAL INSTABILITY FROM NORTHEAST MARYLAND THROUGH THE LEHIGH VALLEY. THE 1200 UTC NAM IS LESS BULLISH...AND AT THIS POINT WOULD BE INCLINED TO KEEP THE FORECAST DRY. FOR MONDAY NIGHT AND TUESDAY...MID LEVEL RIDGING REASSERTS ITSELF FROM THE CAROLINA. THIS WILL ALLOW EVEN WARM AIR TO MOVE NORTH INTO THE FORECAST AREA. HIGHER DEW POINTS MAY LEAD TO MARGINAL INSTABILITY FOR A GREATER PORTION OF THE FORECAST AREA. HOWEVER... WITH NO FOCUS IN PLACE...WILL OPT TO KEEP TUESDAY DRY AS WELL. 850 MB TEMPERATURES WARM BY ANOTHER 4 DEGREES FOR TUESDAY. THIS MAY ALLOW SOME AREAS TO REACH 90 DEGREES TUESDAY AFTERNOON. THIS WOULD BE A BIT ABOVE THE MOS GUIDANCE FOR TUESDAY. WITH THE AIRMASS MOISTENING...THE EXTRA HEAT MAY GOING INTO WARMING THE MOISTURE IN THE AIR AND NOT THE AIR ITSELF. WILL KEEP MOST HIGH TEMPERATURES JUST BELOW THE 90 DEGREE MARK. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. WITH HIGHS IN THE MID AND UPPER 80S...AND MAYBE NEAR 90...IT WAS DECIDED TO CARRY A MENTION OF THUNDER FOR WEDNESDAY AFTERNOON AND INTO THE EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL-LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... A LARGE STORM SYSTEM OVER SOUTHEASTERN CANADA COMBINED WITH COOLER AIR MOVING OVER THE AREA HAS PRODUCED A TIGHTENED PRESSURE GRADIENT ACROSS THE REGION. THIS HAS RESULTED IN SUSTAINED WINDS GENERALLY OF 15 TO 20 KNOTS WITH GUSTS TO 30 KNOTS. THIS IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON, HOWEVER ONCE THE VERTICAL MIXING LESSENS WITH THE LOSS OF DAYTIME HEATING THE WINDS WILL DIMINISH THIS EVENING AND OVERNIGHT, WITH SOME TERMINALS EVEN HAVING THE WIND GO LIGHT AND VARIABLE. THIS WILL ALSO BE HELPED AS THE PRESSURE GRADIENT IS FORECAST TO RELAX THROUGH THE NIGHT. AS A RESULT, WE MAINTAINED THE STEPPING DOWN APPROACH WITH THE WINDS THROUGH THE FIRST HALF OF TONIGHT. OVERALL, THE WINDS WILL BE FROM THE WEST. DUE TO LOCAL AFFECTS, WE KEPT KTTN MORE NORTHWEST THAN THE OTHER TERMINALS INTO THIS EVENING. THE COLDER AIR ARRIVING ALOFT COMBINED WITH SURFACE HEATING HAS ALLOWED A GOOD DEAL OF STRATOCUMULUS TO DEVELOP AND OVERSPREAD THE BULK OF THE AREA THIS AFTERNOON. WE THEREFORE INCREASED THE COVERAGE FOR AWHILE THIS AFTERNOON WITH THE GREATEST AT KRDG AND KABE, WITH A TEMPO GROUP FOR BROKEN COVERAGE AT TIMES AT KTTN AND KPNE. KPHL MAY GO BROKEN COVERAGE FOR A TIME AS WELL. FARTHER TO THE SOUTH AND EAST, JUST FEW TO SCATTERED COVERAGE WAS USED. OVERALL THOUGH, VFR IS EXPECTED TO CONTINUE. THESE CLOUDS ARE EXPECTED TO DISSIPATE FROM SOUTHEAST TO NORTHWEST THROUGH THE EVENING. FOR SUNDAY, HIGH PRESSURE TO OUR WEST BUILDS CLOSER ALLOWING THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE ALTHOUGH SPEEDS WILL BE LESS THAN TODAY. OVERALL WE WENT WITH A 10 TO 15 KNOT WIND ALTHOUGH DID INCLUDE SOME GUSTINESS FROM ABOUT MID MORNING ON AT THE MORE PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT HAS OCCURRED TODAY AS THE AIRMASS WARMS A LITTLE BIT. THEREFORE WE ONLY CARRIED FEW TO SCATTERED STRATOCUMULUS WITH THE GREATEST AT KRDG AND KABE. OUTLOOK... HIGH PRESSURE SETTLES OVER OUR AREA LATE SUNDAY AND CONTINUES MONDAY BEFORE SLIDING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF A COLD FRONT, HOWEVER THIS COLD FRONT DOES APPEAR TO MOVE INTO OUR AREA UNTIL WEDNESDAY THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... A LARGE STORM ACROSS SOUTHEASTERN CANADA AND HIGH PRESSURE WELL TO OUR WEST HAS ALLOWED A TIGHT PRESSURE GRADIENT TO BECOME ESTABLISHED ACROSS OUR AREA. AS COLDER AIR ALOFT MOVES ACROSS THE AREA, THIS HAS HELPED TO INCREASE THE VERTICAL MIXING. HOWEVER, THE WINDS OVER MOST OF THE WATERS HAVE ACTUALLY COME DOWN SOME THIS AFTERNOON AND THAT APPEARS TO BE RELATED TO A WARMER BOUNDARY LAYER OVER THE WARM WATER. THIS HAS REDUCED THE OVERALL VERTICAL MIXING ESPECIALLY AWAY FROM THE COAST. THE SEAS HOWEVER ARE STILL UP, GENERALLY IN THE 3 TO 6 FOOT RANGE WITH THE HIGHEST FARTHER OFFSHORE. THESE ARE EXPECTED TO GRADUALLY SUBSIDE TONIGHT AS THE OFFSHORE FLOW CONTINUES BUT DIMINISHES WITH TIME. A POSSIBLE FLY IN THE OINTMENT IS THAT AS THE BOUNDARY LAYER COOLS AND THE COLDER AIR ALOFT MOVES OVER THE WARM WATERS, THE VERTICAL MIXING WOULD INCREASE FOR A TIME TONIGHT BEFORE THE TIGHTEST PRESSURE GRADIENT SHIFTS NORTHWARD. THE FORECAST SOUNDINGS ARE HINTING AT THIS, ESPECIALLY ACROSS THE NORTHERN WATERS. ACROSS THE SOUTH, THE NAM/WRF FORECAST SOUNDINGS ARE LOOKING A BIT TO AGGRESSIVE WITH THE VERTICAL MIXING COMPARED TO THE GFS. BASED ON THE WIND TRENDS AT BUOY 44009, THE GFS LOOKS TO HAVE A BETTER HANDLE ON THIS. GIVEN THIS, WE WILL KEEP THE SMALL CRAFT ADVISORY ACROSS THE SOUTHERN WATERS AND DELAWARE BAY UNTIL 00Z TONIGHT, THEN EXTEND THE NORTHERN COASTAL WATERS UNTIL 04Z TO ACCOUNT FOR THE LINGERING PRESSURE GRADIENT HERE LONGER. ADDITIONAL ADJUSTMENTS MAY BE NEEDED BASED ON TRENDS DURING THE EVENING. OTHERWISE, HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA FROM THE WEST SUNDAY AND MONDAY. THE OFFSHORE FLOW WILL BE IN THE 10 TO 15 KNOT RANGE SUNDAY BUT NOT AS GUSTY AS TODAY AS THE PRESSURE GRADIENT CONTINUES TO SHIFT NORTH AND OUT OF OUR AREA. THE AREA OF HIGH PRESSURE THEN SHIFTS TO OUR EAST TUESDAY WITH A RETURN FLOW BECOMING ESTABLISHED. AS THE FLOW IS LIGHTER MONDAY, SEA/BAY BREEZE CIRCULATIONS MAY OCCUR. THE SOUTHERLY FLOW WELL AHEAD OF AN ADVANCING COLD FRONT TUESDAY MAY ALLOW SOME INCREASE IN SPEEDS BUT AS OF NOW IT LOOKS TO BE BELOW ADVISORY CRITERIA GIVEN A WARMER AIRMASS IN PLACE. THE COLD FRONT DOES APPEAR TO MOVE INTO OUR AREA UNTIL LATE WEDNESDAY THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES WILL BE NEAR 30 PERCENT FOR A LARGE PORTION OF THE AREA SUNDAY AFTERNOON...BUT HIGH TEMPERATURES A FEW DEGREES LOWER THAN TODAY MAY KEEP THESE VALUES HIGHER. THE GRADIENT DOES NOT APPEAR TO SUPPORT WIND GUSTS ABOVE 20 KNOTS OVER MUCH OF THE AREA. WILL HOLD OFF ON A FIRE WEATHER WATCH FOR SUNDAY. THIS CAN BE REVISITED SUNDAY...IF WINDS ARE STRONGER THAN FORECAST OR IF IT APPEARS AS THOUGH RELATIVE HUMIDITY VALUES WILL DROP BELOW 30 PERCENT. && .RIP CURRENTS... THE WAVES ARE STILL RUNNING NEAR 4 FEET IN THE SURF ZONE ALONG WITH THEM BEING MORE OF A LONGER PERIOD. SOME COASTAL WEB CAMS INDICATE THE SURF CONTINUES TO BE ON THE ROUGH SIDE. THEREFORE, A MODERATE RISK OF RIP CURRENTS REMAINS IN EFFECT THROUGH THIS EVENING. A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT HIGHLIGHTING THE MODERATE RISK REMAINS VALID UNTIL 00Z TONIGHT. THE OVERALL CONDITIONS ARE ANTICIPATED TO IMPROVE FOR SUNDAY AND LABOR DAY AS THE SEAS AND WINDS LOWER. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-452>455. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450-451. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES AVIATION...GORSE MARINE...GORSE FIRE WEATHER...HAYES RIP CURRENTS...GORSE 000 FXUS61 KPHI 041915 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 315 PM EDT SAT SEP 4 2010 .SYNOPSIS... HIGH PRESSURE OVER THE MIDWEST WILL BUILD EAST...REACHING THE MID ATLANTIC COAST SUNDAY NIGHT AND MONDAY. THE RETURN FLOW AROUND THE HIGH WILL BRING WARMER AND MORE HUMID CONDITIONS FOR THE EARLY PART OF THE UPCOMING WEEK. A COLD FRONT WILL APPROACH THE REGION WEDNESDAY...THEN CROSS THE REGION WEDNESDAY EVENING. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH FROM ONTARIO FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE MID LEVEL LONG WAVE THROUGH WILL CROSS THE REGION THIS EVENING. THERE MAY BE ENOUGH INSTABILITY FOR A FEW SPRINKLES ACROSS THE HIGHER TERRAIN LATE THIS AFTERNOON AND THIS EVENING. OTHERWISE... WITH THE LOSS OF DAYTIME HEATING...THE CUMULUS AND STRATOCUMULUS SHOULD MELT AWAY THIS EVENING. THIS MAY TAKE LONGER ACROSS THE NORTH WHERE CLOUDS FROM THE GREAT LAKES MAY CONTINUE TO STREAM EAST. THE BEST GRADIENT WILL REMAIN OVER THE FORECAST AREA THROUGH THE EVENING HOURS. FOR MOST PLACES...THE GUSTINESS LATE THIS AFTERNOON SHOULD CEASE...BUT WINDS MAY NOT BECOME LIGHT UNTIL LATER THIS EVENING. WITH DEW POINTS AS LOW AS THEY ARE THIS EVENING...LIGHT WINDS MAY ALLOW FOR RADIATIONAL COOLING PROTECTED SPOTS. WILL LEAN TOWARD THE COOLER GFS MOS FOR LOWS...BUT NOT MUCH BELOW THIS AS IT WILL BE THE FIRST NIGHT IN THIS AIRMASS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... WITH THE REGION IN CYCLONIC FLOW IN THE MID LEVELS SUNDAY...WOULD EXPECT CUMULUS TO DEVELOP ONCE AGAIN AS CONVECTIVE TEMPERATURES SHOULD BE WITHIN REACH. WHILE THERE WILL BE SOME GRADIENT OVER THE REGION...ESPECIALLY IN THE MORNING...WOULD EXPECT WINDS OVERALL TO BE LIGHT THAN THIS AFTERNOON. 850 MB TEMPERATURES SUGGEST TEMPERATURES NEAR OR JUST BELOW HIGHS REACHED TODAY. LEANED TOWARD THE COOLER GFS FOR THIS REASON FOR HIGHS. THE SURFACE HIGH WILL REACH THE MID ATLANTIC COAST SUNDAY NIGHT... WITH CYCLONIC FLOW IN PLACE IN THE MID LEVELS. THE GRADIENT SHOULD DROP OFF MORE QUICKLY SUNDAY EVENING. THIS AND CLEAR SKIES SHOULD BE MORE CONDUCIVE TO A GOOD RADIATIONAL COOLING NIGHT...AND FOR THIS REASON LEANED TOWARD THE COOLER GFS MOS NUMBERS AWAY FROM URBAN AREAS. THE RADIATIONAL COOLING SHOULD ALLOW VALLEY FOG TO FORM EARLY MONDAY MORNING...DESPITE THE RELATIVELY LOW DEW POINTS...AND THIS WILL BE RETAINED IN THE FORECAST. THE RETURN FLOW AROUND THE SURFACE HIGH OFF THE MID ATLANTIC COAST WILL START BRINGING WARMER AND MORE HUMID AIR NORTHWARD. IN THE MID LEVELS...THE FLOW WILL BECOME MORE ZONAL. THE COMBINATION SHOULD RESULT IN SOME CUMULUS DEVELOPMENT...BUT PROBABLY LESS THAN MONDAY. 850 MB TEMPERATURES LOOK TO BE ABOUT 2 DEGREES CELSIUS WARMER MONDAY THAN SUNDAY. WITH THIS IN MIND...LEANED TOWARD THE WARMER GFS MOS NUMBERS FOR HIGHS. THE GRADIENT SHOULD BE LIGHT ENOUGH TO ALLOW SEA/BAY BREEZE CIRCULATIONS TO DEVELOP IN THE AFTERNOON. THE 1200 UTC GFS IS MORE AGGRESSIVE WITH THE RETURN OF THE LOW LEVEL MOISTURE INTO THE FORECAST AREA MONDAY AFTERNOON. HIGHER PRECIPITABLE WATER VALUES...AND DECENT MID LEVEL LAPSE RATES...WOULD SUGGEST MARGINAL INSTABILITY FROM NORTHEAST MARYLAND THROUGH THE LEHIGH VALLEY. THE 1200 UTC NAM IS LESS BULLISH...AND AT THIS POINT WOULD BE INCLINED TO KEEP THE FORECAST DRY. FOR MONDAY NIGHT AND TUESDAY...MID LEVEL RIDGING REASSERTS ITSELF FROM THE CAROLINA. THIS WILL ALLOW EVEN WARM AIR TO MOVE NORTH INTO THE FORECAST AREA. HIGHER DEW POINTS MAY LEAD TO MARGINAL INSTABILITY FOR A GREATER PORTION OF THE FORECAST AREA. HOWEVER... WITH NO FOCUS IN PLACE...WILL OPT TO KEEP TUESDAY DRY AS WELL. 850 MB TEMPERATURES WARM BY ANOTHER 4 DEGREES FOR TUESDAY. THIS MAY ALLOW SOME AREAS TO REACH 90 DEGREES TUESDAY AFTERNOON. THIS WOULD BE A BIT ABOVE THE MOS GUIDANCE FOR TUESDAY. WITH THE AIRMASS MOISTENING...THE EXTRA HEAT MAY GOING INTO WARMING THE MOISTURE IN THE AIR AND NOT THE AIR ITSELF. WILL KEEP MOST HIGH TEMPERATURES JUST BELOW THE 90 DEGREE MARK. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A RATHER PROGRESSIVE AND MOSTLY ZONAL PATTERN IS PROGGED THIS COMING WEEK AND INTO THE WEEKEND...AS THE JET STREAM IS EXPECTED TO BE SLIGHTLY NORTH OF OUR LATITUDE. A COUPLE OF SHORT WAVES APPEAR TO BE PASSING THROUGH HOWEVER...AND ALONG WITH THEIR SURFACE REFLECTIONS THIS WILL PRESENT A COUPLE OF OPPORTUNITIES FOR POSSIBLE PRECIPITATION...BUT WITH THE DROUGHT PATTERN OF THIS SUMMER PRECIPITATION SHOULD BE SPARSE. THE MODELS ARE RATHER CONSISTENT IN SHOWING AN UPPER LEVEL SHORT WAVE MOVING QUICKLY THROUGH THE AREA ABOUT WEDNESDAY AND INTO WEDNESDAY EVENING. WITH HIGHS IN THE MID AND UPPER 80S...AND MAYBE NEAR 90...IT WAS DECIDED TO CARRY A MENTION OF THUNDER FOR WEDNESDAY AFTERNOON AND INTO THE EVENING. HIGH PRESSURE SHOULD FOLLOW FOR THE LATTER PORTION OF THE WEEK...AND MAY BE STRONG AS THE GFS SHOWS A FULL-LATITUDE RIDGE EMANATING FROM THE CLOSED HIGH IN THE DEEP SOUTH AND ALONG THE GULF COAST. ANOTHER UPPER TROUGH IS SEEN TO APPROACH DURING NEXT WEEKEND...SO SLIGHT CHANCE PROBABILITIES WERE USED FOR SHOWERS FOR SATURDAY NIGHT. THE END OF THE WEEK SHOULD BE COOLER THAN THE MIDDLE PART IN THE WAKE OF THE FRONTAL PASSAGE WEDNESDAY EVENING. HPC GUIDANCE TEMPERATURES WERE DEEMED TO BE WORKING WELL AND WERE USED. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... A LARGE STORM SYSTEM OVER SOUTHEASTERN CANADA COMBINED WITH COOLER AIR MOVING OVER THE AREA HAS PRODUCED A TIGHTENED PRESSURE GRADIENT ACROSS THE REGION. THIS HAS RESULTED IN SUSTAINED WINDS GENERALLY OF 15 TO 20 KNOTS WITH GUSTS TO 30 KNOTS. THIS IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON, HOWEVER ONCE THE VERTICAL MIXING LESSENS WITH THE LOSS OF DAYTIME HEATING THE WINDS WILL DIMINISH THIS EVENING AND OVERNIGHT, WITH SOME TERMINALS EVEN HAVING THE WIND GO LIGHT AND VARIABLE. THIS WILL ALSO BE HELPED AS THE PRESSURE GRADIENT IS FORECAST TO RELAX THROUGH THE NIGHT. AS A RESULT, WE MAINTAINED THE STEPPING DOWN APPROACH WITH THE WINDS THROUGH THE FIRST HALF OF TONIGHT. OVERALL, THE WINDS WILL BE FROM THE WEST. DUE TO LOCAL AFFECTS, WE KEPT KTTN MORE NORTHWEST THAN THE OTHER TERMINALS INTO THIS EVENING. THE COLDER AIR ARRIVING ALOFT COMBINED WITH SURFACE HEATING HAS ALLOWED A GOOD DEAL OF STRATOCUMULUS TO DEVELOP AND OVERSPREAD THE BULK OF THE AREA THIS AFTERNOON. WE THEREFORE INCREASED THE COVERAGE FOR AWHILE THIS AFTERNOON WITH THE GREATEST AT KRDG AND KABE, WITH A TEMPO GROUP FOR BROKEN COVERAGE AT TIMES AT KTTN AND KPNE. KPHL MAY GO BROKEN COVERAGE FOR A TIME AS WELL. FARTHER TO THE SOUTH AND EAST, JUST FEW TO SCATTERED COVERAGE WAS USED. OVERALL THOUGH, VFR IS EXPECTED TO CONTINUE. THESE CLOUDS ARE EXPECTED TO DISSIPATE FROM SOUTHEAST TO NORTHWEST THROUGH THE EVENING. FOR SUNDAY, HIGH PRESSURE TO OUR WEST BUILDS CLOSER ALLOWING THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE ALTHOUGH SPEEDS WILL BE LESS THAN TODAY. OVERALL WE WENT WITH A 10 TO 15 KNOT WIND ALTHOUGH DID INCLUDE SOME GUSTINESS FROM ABOUT MID MORNING ON AT THE MORE PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT HAS OCCURRED TODAY AS THE AIRMASS WARMS A LITTLE BIT. THEREFORE WE ONLY CARRIED FEW TO SCATTERED STRATOCUMULUS WITH THE GREATEST AT KRDG AND KABE. OUTLOOK... HIGH PRESSURE SETTLES OVER OUR AREA LATE SUNDAY AND CONTINUES MONDAY BEFORE SLIDING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF A COLD FRONT, HOWEVER THIS COLD FRONT DOES APPEAR TO MOVE INTO OUR AREA UNTIL WEDNESDAY THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... A LARGE STORM ACROSS SOUTHEASTERN CANADA AND HIGH PRESSURE WELL TO OUR WEST HAS ALLOWED A TIGHT PRESSURE GRADIENT TO BECOME ESTABLISHED ACROSS OUR AREA. AS COLDER AIR ALOFT MOVES ACROSS THE AREA, THIS HAS HELPED TO INCREASE THE VERTICAL MIXING. HOWEVER, THE WINDS OVER MOST OF THE WATERS HAVE ACTUALLY COME DOWN SOME THIS AFTERNOON AND THAT APPEARS TO BE RELATED TO A WARMER BOUNDARY LAYER OVER THE WARM WATER. THIS HAS REDUCED THE OVERALL VERTICAL MIXING ESPECIALLY AWAY FROM THE COAST. THE SEAS HOWEVER ARE STILL UP, GENERALLY IN THE 3 TO 6 FOOT RANGE WITH THE HIGHEST FARTHER OFFSHORE. THESE ARE EXPECTED TO GRADUALLY SUBSIDE TONIGHT AS THE OFFSHORE FLOW CONTINUES BUT DIMINISHES WITH TIME. A POSSIBLE FLY IN THE OINTMENT IS THAT AS THE BOUNDARY LAYER COOLS AND THE COLDER AIR ALOFT MOVES OVER THE WARM WATERS, THE VERTICAL MIXING WOULD INCREASE FOR A TIME TONIGHT BEFORE THE TIGHTEST PRESSURE GRADIENT SHIFTS NORTHWARD. THE FORECAST SOUNDINGS ARE HINTING AT THIS, ESPECIALLY ACROSS THE NORTHERN WATERS. ACROSS THE SOUTH, THE NAM/WRF FORECAST SOUNDINGS ARE LOOKING A BIT TO AGGRESSIVE WITH THE VERTICAL MIXING COMPARED TO THE GFS. BASED ON THE WIND TRENDS AT BUOY 44009, THE GFS LOOKS TO HAVE A BETTER HANDLE ON THIS. GIVEN THIS, WE WILL KEEP THE SMALL CRAFT ADVISORY ACROSS THE SOUTHERN WATERS AND DELAWARE BAY UNTIL 00Z TONIGHT, THEN EXTEND THE NORTHERN COASTAL WATERS UNTIL 04Z TO ACCOUNT FOR THE LINGERING PRESSURE GRADIENT HERE LONGER. ADDITIONAL ADJUSTMENTS MAY BE NEEDED BASED ON TRENDS DURING THE EVENING. OTHERWISE, HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA FROM THE WEST SUNDAY AND MONDAY. THE OFFSHORE FLOW WILL BE IN THE 10 TO 15 KNOT RANGE SUNDAY BUT NOT AS GUSTY AS TODAY AS THE PRESSURE GRADIENT CONTINUES TO SHIFT NORTH AND OUT OF OUR AREA. THE AREA OF HIGH PRESSURE THEN SHIFTS TO OUR EAST TUESDAY WITH A RETURN FLOW BECOMING ESTABLISHED. AS THE FLOW IS LIGHTER MONDAY, SEA/BAY BREEZE CIRCULATIONS MAY OCCUR. THE SOUTHERLY FLOW WELL AHEAD OF AN ADVANCING COLD FRONT TUESDAY MAY ALLOW SOME INCREASE IN SPEEDS BUT AS OF NOW IT LOOKS TO BE BELOW ADVISORY CRITERIA GIVEN A WARMER AIRMASS IN PLACE. THE COLD FRONT DOES APPEAR TO MOVE INTO OUR AREA UNTIL LATE WEDNESDAY THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .FIRE WEATHER... RED FLAG WARNING CRITERIA IS BEING MET ACROSS DELAWARE AND MUCH OF SOUTHERN AND CENTRAL NEW JERSEY. CONDITIONS ARE A BIT MORE MARGINAL ACROSS SOUTHEAST PENNSYLVANIA...WHERE RELATIVE HUMIDITY VALUES ARE HOVERING AROUND 32 PERCENT. WILL CONTINUE THE RED FLAG WARNING THROUGH 500 PM. NOT SURE IF THIS NEEDS TO BE EXTENDED...AS WINDS MAY START TO COME DOWN...AND RELATIVE HUMIDITY VALUES WILL START TO RECOVER. RELATIVE HUMIDITY VALUES WILL BE NEAR 30 PERCENT FOR A LARGE PORTION OF THE AREA SUNDAY AFTERNOON...BUT HIGH TEMPERATURES A FEW DEGREES LOWER THAN TODAY MAY KEEP THESE VALUES HIGHER. THE GRADIENT DOES NOT APPEAR TO SUPPORT WIND GUSTS ABOVE 20 KNOTS OVER MUCH OF THE AREA. WILL HOLD OFF ON A FIRE WEATHER WATCH FOR SUNDAY. THIS CAN BE REVISITED SUNDAY...IF WINDS ARE STRONGER THAN FORECAST OR IF IT APPEARS AS THOUGH RELATIVE HUMIDITY VALUES WILL DROP BELOW 30 PERCENT. && .RIP CURRENTS... THE WAVES ARE STILL RUNNING NEAR 4 FEET IN THE SURF ZONE ALONG WITH THEM BEING MORE OF A LONGER PERIOD. SOME COASTAL WEB CAMS INDICATE THE SURF CONTINUES TO BE ON THE ROUGH SIDE. THEREFORE, A MODERATE RISK OF RIP CURRENTS REMAINS IN EFFECT THROUGH THIS EVENING. A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT HIGHLIGHTING THE MODERATE RISK REMAINS VALID UNTIL 00Z TONIGHT. THE OVERALL CONDITIONS ARE ANTICIPATED TO IMPROVE FOR SUNDAY AND LABOR DAY AS THE SEAS AND WINDS LOWER. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ067>071. NJ...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR NJZ012>027. DE...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR DEZ001>004. MD...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR MDZ008-012- 015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-452>455. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450-451. && $$ SYNOPSIS...HAYES NEAR TERM...HAYES SHORT TERM...HAYES LONG TERM.../ AVIATION...GORSE MARINE...GORSE FIRE WEATHER... RIP CURRENTS... 000 FXUS61 KPHI 041735 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 135 PM EDT SAT SEP 4 2010 .SYNOPSIS... THE DRY PATTERN OF THE PAST 10 DAYS LOOKS TO CONTINUE FOR ANOTHER WEEK AS LOW PRESSURE SYSTEMS MOVE ACROSS SOUTHERN CANADA. REFRESHINGLY COOL HIGH PRESSURE IN THE PLAINS WILL MOVE TO THE MID ATLANTIC STATES SUNDAY, THEN BECOME PART OF THE BERMUDA HIGH BY MIDWEEK ENCOURAGING A RETURN OF 90 DEGREE HEAT HERE EITHER TUESDAY OR WEDNESDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST WEDNESDAY WITH A COOLER TREND TO FOLLOW AT THE END OF THE WORKWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE MID LEVEL FLOW OVER THE FORECAST AREA IS TRANSITIONING TO CYCLONIC IN THE WAKE OF EARL AND AHEAD OF A LONG WAVE TROUGH OVER THE GREAT LAKES. THE INITIAL COLD AIR ADVECTION BEHIND THE COLD FRONT THIS MORNING CLEARED THE FORECAST AREA OUT. STARTING TO SEE CUMULUS DEVELOP IN THE COLD AIR ADVECTION...BUT CONVECTIVE TEMPERATURES ARE FAIRLY HIGH RIGHT NOW...SO THIS SHOULD BE LIMITED THIS MORNING. AS THE COLD AIR ADVECTION CONTINUES THIS AFTERNOON...WOULD EXPECT TO SEE CONVECTIVE TEMPERATURES DROP...WITH MORE IN THE WAY OF CUMULUS DEVELOPMENT THIS AFTERNOON. THE SOUTHERN POCONOS AND NORTHWEST JERSEY COULD ALSO SEE CLOUDS FROM THE ACTIVITY OVER THE GREAT LAKES. AT THIS POINT...IT APPEARS AS THOUGH THE LOWER LEVELS SHOULD REMAIN DRY ENOUGH TO PRECLUDE SHOWER ACTIVITY. WILL MONITOR FOR TRENDS AND INSERT SPRINKLES IF NEEDED. ELSEWHERE...WOULD EXPECT THE DRY CONDITIONS TO CONTINUE. 1200 UTC SOUNDINGS...AS WELL AS ACARS SHOULD FROM THE KPHL AREA...SHOW 35 TO 40 KNOTS OF WIND AT THE TOP OF THE MIXED LAYER. THIS WOULD TRANSLATE TO 35 TO POSSIBLY 40 MPH WIND GUSTS THIS AFTERNOON...ESPECIALLY AS A REINFORCING SHOT OF COLD AIR ADVECTION ARRIVES DURING THE MID AFTERNOON. NOT SEEING ENOUGH TO WARRANT A WIND ADVISORY AT THIS TIME. HIGHS LOOK REASONABLE GIVEN MAX TEMPERATURES ON THE 1200 UTC SOUNDINGS. DID LOWER DEW POINTS A BIT FOR THE AFTERNOON AS MIXING FROM 850 MB (AND POSSIBLY JUST ABOVE) WOULD DROP SURFACE DEW POINTS INTO THE LOWER TO MID 40S. THE COMBINATION OF WIND AND DRY AIR DOES RAISE FIRE DANGER CONCERNS. MORE ON THIS IS CONTAINED IN THE FIRE WEATHER SECTION BELOW. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... COOLER THAN NORMAL BOTH TONIGHT AND SUNDAY NIGHT AND NEAR NORMAL MAX TEMP SUNDAY WITH GENERALLY CLEAR SKIES. LIGHT WIND AT NIGHT AND LESS WIND SUNDAY DAYLIGHT HOURS COMPARED TO TODAY-SATURDAY. WARMING UP MONDAY AND ESPECIALLY TUESDAY WHEN THE DEWPOINT ALSO NOTICEABLY INCREASES...BUT A DRY PATTERN WITH RIDGING ALOFT. HASNT RAINED OF ANY SIGNIFICANCE SINCE THE 22ND-24TH OF AUGUST. GRIDDED FORECAST DATA OFFERS >97 PCT RH FOR AN HR OR 2 EARLY MON AND TUE MORNINGS AND HAVE PATCHY 2SM FOG WHERE GRIDS INDICATE THIS RH. GREATER CONFIDENCE OF PATCHY FOG EARLY TUE MORNING AS DEWPOINTS COME UP STEADILY TO 60 PLUS AND STILL HAVE LIGHT WIND WITH FAIR SKIES. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE UPPER PATTERN SHOULD REMAIN PROGRESSIVE THROUGH THE PERIOD. AN UPPER LEVEL RIDGE IS EXPECTED TO BUILD OVER OUR REGION FROM THE WEST ON TUESDAY. AN UPPER LEVEL TROUGH IS ANTICIPATED TO FOLLOW AND IT SHOULD PASS OVER THE NORTHEASTERN STATES ON WEDNESDAY AND THURSDAY. ANOTHER UPPER LEVEL RIDGE IS FORECAST TO BEGIN BUILDING TOWARD OUR REGION FROM THE WEST ON FRIDAY. AT THE SURFACE, HIGH PRESSURE SHOULD CONTINUE TO INFLUENCE EASTERN PENNSYLVANIA, NEW JERSEY, DELAWARE AND NORTHEASTERN MARYLAND FROM MONDAY NIGHT INTO WEDNESDAY. A COLD FRONT FROM THE NORTHWEST IS FORECAST TO PASS THROUGH OUR REGION FROM WEDNESDAY NIGHT INTO EARLY THURSDAY. THE BOUNDARY SHOULD HAVE LITTLE MOISTURE ASSOCIATED WITH IT. AS A RESULT, WE HAVE CARRIED LITTLE MENTION OF PRECIPITATION. THE AIR MASS IS EXPECTED TO WARM EFFICIENTLY FOR TUESDAY AND WEDNESDAY. DAYTIME MAXIMUM TEMPERATURES SHOULD RISE NEAR 90 DEGREES BOTH DAYS, EXCEPT IN THE HIGHER ELEVATIONS AND AT LOCATIONS NEAR THE COAST. THE PASSAGE OF THE COLD FRONT EARLY ON THURSDAY SHOULD CAUSE MAXIMUM TEMPERATURES TO DROP BACK AROUND 80 DEGREES FOR THURSDAY AND FRIDAY. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A LARGE STORM SYSTEM OVER SOUTHEASTERN CANADA COMBINED WITH COOLER AIR MOVING OVER THE AREA HAS PRODUCED A TIGHTENED PRESSURE GRADIENT ACROSS THE REGION. THIS HAS RESULTED IN SUSTAINED WINDS GENERALLY OF 15 TO 20 KNOTS WITH GUSTS TO 30 KNOTS. THIS IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON, HOWEVER ONCE THE VERTICAL MIXING LESSENS WITH THE LOSS OF DAYTIME HEATING, THE WINDS WILL DIMINISH TONIGHT WITH SOME TERMINALS EVEN HAVING THE WIND GO LIGHT AND VARIABLE BY LATE EVENING. THIS WILL ALSO BE HELPED AS THE PRESSURE GRADIENT IS FORECAST TO RELAX THROUGH THE NIGHT. AS A RESULT, WE MAINTAINED THE STEPPING DOWN APPROACH WITH THE WINDS THROUGH THE FIRST HALF OF TONIGHT. OVERALL, THE WINDS WILL BE FROM THE WEST. DUE TO LOCAL AFFECTS, WE KEPT KTTN MORE NORTHWEST THAN THE OTHER TERMINALS INTO THIS EVENING. THE COLDER AIR ARRIVING ALOFT COMBINED WITH SURFACE HEATING HAS ALLOWED A GOOD DEAL OF STRATOCUMULUS TO DEVELOP AND OVERSPREAD THE BULK OF THE AREA THIS AFTERNOON. WE THEREFORE INCREASED THE COVERAGE FOR AWHILE THIS AFTERNOON WITH THE GREATEST AT KRDG AND KABE, WITH A TEMPO GROUP FOR BROKEN COVERAGE AT TIMES AT KTTN AND KPNE. KPHL MAY GO BROKEN COVERAGE FOR A TIME AS WELL. FARTHER TO THE SOUTH AND EAST, JUST FEW TO SCATTERED COVERAGE WAS USED. OVERALL THOUGH, VFR IS EXPECTED TO CONTINUE. THESE CLOUDS ARE EXPECTED TO DISSIPATE FROM SOUTHEAST TO NORTHWEST THROUGH THE EVENING. FOR SUNDAY, HIGH PRESSURE TO OUR WEST BUILDS CLOSER ALLOWING THE PRESSURE GRADIENT TO LIFT NORTHWARD. THERE WILL STILL BE A BREEZE FOR AWHILE ALTHOUGH SPEEDS WILL BE LESS THAN TODAY. OVERALL WE WENT WITH A 10 TO 15 KNOT WIND ALTHOUGH DID INCLUDE SOME GUSTINESS FROM ABOUT MID MORNING ON AT THE MORE PRONE TERMINALS GIVEN ENOUGH VERTICAL MIXING. AGAIN, THE WINDS WILL BE FROM A WESTERLY DIRECTION. CLOUD COVER SUNDAY SHOULD BE LESS THAN WHAT HAS OCCURRED TODAY AS THE AIRMASS WARMS A LITTLE BIT. THEREFORE WE ONLY CARRIED FEW TO SCATTERED STRATOCUMULUS WITH THE GREATEST AT KRDG AND KABE. OUTLOOK... HIGH PRESSURE SETTLES OVER OUR AREA LATE SUNDAY AND CONTINUES MONDAY BEFORE SLIDING TO OUR EAST TUESDAY. A SOUTHWESTERLY FLOW WILL OCCUR MONDAY WELL AHEAD OF A COLD FRONT, HOWEVER THIS COLD FRONT DOES APPEAR TO MOVE INTO OUR AREA UNTIL WEDNESDAY THEN BE TO OUR EAST THURSDAY. AS OF NOW, THERE IS JUST A SMALL CHANCE OF A SHOWER OR THUNDERSTORM WITH THE COLD FRONT. && .MARINE... TROPICAL STORM EARL CONTINUES ITS NORTHEAST TREK ACROSS THE CANADIAN MARITIMES. HIGH PRESSURE WILL GRADUALLY BUILD IN AND REMAIN OVER THE REGION THROUGH THE EARLY PART OF NEXT WEEK. SEAS WILL CONTINUE TO DECREASE AS EARL LOSES ITS GRIP ON THE AREA. HOWEVER, FROPA AND THEN THE TIGHT PRESSURE GRADIENT BTWN EARL AND THE BUILDING HIGH WILL MAKE FOR GUSTY W TO NW WINDS. GUSTS TO 30 KT CAN BE EXPECTED. LATEST GUIDANCE INDICATES THAT THE WINDS COULD REMAIN GUSTY THROUGH SUNSET, SO WILL EXTEND THE SCA UNTIL 05/00Z ON ALL OF THE AREA WATERS. AFTER THE WINDS DECREASE TONIGHT, EXPECT MUCH IMPROVED AND RELATIVELY TRANQUIL CONDS ON THE AREA WATERS INTO EARLY NEXT WEEK. && .FIRE WEATHER... AFTER CONSULTING WITH MARYLAND FOREST OFFICIALS...HAVE EXPANDED THE RED FLAG WARNING TO INCLUDE EASTERN MARYLAND. ALSO INCLUDED THE REST OF SOUTHEAST PENNSYLVANIA AND DELAWARE. ALL OF THE ABOVE AREAS SHOULD REACH CRITERIA THIS AFTERNOON. 1200 UTC SOUNDINGS SHOW THE POTENTIAL FOR 35 MPH WIND GUSTS...AS WELL AS MIXING DRY AIR FROM NEAR 850 MB TO THE SURFACE. THIS WILL RESULT IN DEW POINTS DROPPING INTO THE LOWER TO MID 40S (WHICH IS OCCURRING IN SOME PLACES ALREADY). LEFT OUT THE LEHIGH VALLEY AND NORTHWEST NEW JERSEY...WHERE DEVELOPING CLOUDINESS SHOULD KEEP MINIMUM RELATIVE HUMIDITY VALUES ABOVE 30 PERCENT. && .RIP CURRENTS... SINCE THE SEAS ARE STILL RUNNING ON THE HIGH SIDE IN THE SURF ZONE ALONG WITH THEM BEING MORE OF A LONGER PERIOD, THE RIP CURRENT RISK IS A SOLID MODERATE RATING TODAY. GIVEN THIS IS A HOLIDAY WEEKEND, WE OPTED TO ISSUE A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT TO HIGHLIGHT THE MODERATE RISK. CONDITIONS MAY IMPROVE SOME TOWARD EVENING AND SHOULD BE MUCH IMPROVED FOR THE REMAINDER OF THE LABOR DAY WEEKEND AS THE SEAS AND WINDS LOWER. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ067>071. NJ...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR NJZ012>027. DE...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR DEZ001>004. MD...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR MDZ008-012- 015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM...IOVINO AVIATION...GORSE MARINE...NIERENBERG FIRE WEATHER...DRAG/HAYES RIP CURRENTS...GORSE 000 FXUS61 KPHI 041424 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1024 AM EDT SAT SEP 4 2010 .SYNOPSIS... THE DRY PATTERN OF THE PAST 10 DAYS LOOKS TO CONTINUE FOR ANOTHER WEEK AS LOW PRESSURE SYSTEMS MOVE ACROSS SOUTHERN CANADA. REFRESHINGLY COOL HIGH PRESSURE IN THE PLAINS WILL MOVE TO THE MID ATLANTIC STATES SUNDAY, THEN BECOME PART OF THE BERMUDA HIGH BY MIDWEEK ENCOURAGING A RETURN OF 90 DEGREE HEAT HERE EITHER TUESDAY OR WEDNESDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST WEDNESDAY WITH A COOLER TREND TO FOLLOW AT THE END OF THE WORKWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE MID LEVEL FLOW OVER THE FORECAST AREA IS TRANSITIONING TO CYCLONIC IN THE WAKE OF EARL AND AHEAD OF A LONG WAVE TROUGH OVER THE GREAT LAKES. THE INITIAL COLD AIR ADVECTION BEHIND THE COLD FRONT THIS MORNING CLEARED THE FORECAST AREA OUT. STARTING TO SEE CUMULUS DEVELOP IN THE COLD AIR ADVECTION...BUT CONVECTIVE TEMPERATURES ARE FAIRLY HIGH RIGHT NOW...SO THIS SHOULD BE LIMITED THIS MORNING. AS THE COLD AIR ADVECTION CONTINUES THIS AFTERNOON...WOULD EXPECT TO SEE CONVECTIVE TEMPERATURES DROP...WITH MORE IN THE WAY OF CUMULUS DEVELOPMENT THIS AFTERNOON. THE SOUTHERN POCONOS AND NORTHWEST JERSEY COULD ALSO SEE CLOUDS FROM THE ACTIVITY OVER THE GREAT LAKES. AT THIS POINT...IT APPEARS AS THOUGH THE LOWER LEVELS SHOULD REMAIN DRY ENOUGH TO PRECLUDE SHOWER ACTIVITY. WILL MONITOR FOR TRENDS AND INSERT SPRINKLES IF NEEDED. ELSEWHERE...WOULD EXPECT THE DRY CONDITIONS TO CONTINUE. 1200 UTC SOUNDINGS...AS WELL AS ACARS SHOULD FROM THE KPHL AREA...SHOW 35 TO 40 KNOTS OF WIND AT THE TOP OF THE MIXED LAYER. THIS WOULD TRANSLATE TO 35 TO POSSIBLY 40 MPH WIND GUSTS THIS AFTERNOON...ESPECIALLY AS A REINFORCING SHOT OF COLD AIR ADVECTION ARRIVES DURING THE MID AFTERNOON. NOT SEEING ENOUGH TO WARRANT A WIND ADVISORY AT THIS TIME. HIGHS LOOK REASONABLE GIVEN MAX TEMPERATURES ON THE 1200 UTC SOUNDINGS. DID LOWER DEW POINTS A BIT FOR THE AFTERNOON AS MIXING FROM 850 MB (AND POSSIBLY JUST ABOVE) WOULD DROP SURFACE DEW POINTS INTO THE LOWER TO MID 40S. THE COMBINATION OF WIND AND DRY AIR DOES RAISE FIRE DANGER CONCERNS. MORE ON THIS IS CONTAINED IN THE FIRE WEATHER SECTION BELOW. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... COOLER THAN NORMAL BOTH TONIGHT AND SUNDAY NIGHT AND NEAR NORMAL MAX TEMP SUNDAY WITH GENERALLY CLEAR SKIES. LIGHT WIND AT NIGHT AND LESS WIND SUNDAY DAYLIGHT HOURS COMPARED TO TODAY-SATURDAY. WARMING UP MONDAY AND ESPECIALLY TUESDAY WHEN THE DEWPOINT ALSO NOTICEABLY INCREASES...BUT A DRY PATTERN WITH RIDGING ALOFT. HASNT RAINED OF ANY SIGNIFICANCE SINCE THE 22ND-24TH OF AUGUST. GRIDDED FORECAST DATA OFFERS >97 PCT RH FOR AN HR OR 2 EARLY MON AND TUE MORNINGS AND HAVE PATCHY 2SM FOG WHERE GRIDS INDICATE THIS RH. GREATER CONFIDENCE OF PATCHY FOG EARLY TUE MORNING AS DEWPOINTS COME UP STEADILY TO 60 PLUS AND STILL HAVE LIGHT WIND WITH FAIR SKIES. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE UPPER PATTERN SHOULD REMAIN PROGRESSIVE THROUGH THE PERIOD. AN UPPER LEVEL RIDGE IS EXPECTED TO BUILD OVER OUR REGION FROM THE WEST ON TUESDAY. AN UPPER LEVEL TROUGH IS ANTICIPATED TO FOLLOW AND IT SHOULD PASS OVER THE NORTHEASTERN STATES ON WEDNESDAY AND THURSDAY. ANOTHER UPPER LEVEL RIDGE IS FORECAST TO BEGIN BUILDING TOWARD OUR REGION FROM THE WEST ON FRIDAY. AT THE SURFACE, HIGH PRESSURE SHOULD CONTINUE TO INFLUENCE EASTERN PENNSYLVANIA, NEW JERSEY, DELAWARE AND NORTHEASTERN MARYLAND FROM MONDAY NIGHT INTO WEDNESDAY. A COLD FRONT FROM THE NORTHWEST IS FORECAST TO PASS THROUGH OUR REGION FROM WEDNESDAY NIGHT INTO EARLY THURSDAY. THE BOUNDARY SHOULD HAVE LITTLE MOISTURE ASSOCIATED WITH IT. AS A RESULT, WE HAVE CARRIED LITTLE MENTION OF PRECIPITATION. THE AIR MASS IS EXPECTED TO WARM EFFICIENTLY FOR TUESDAY AND WEDNESDAY. DAYTIME MAXIMUM TEMPERATURES SHOULD RISE NEAR 90 DEGREES BOTH DAYS, EXCEPT IN THE HIGHER ELEVATIONS AND AT LOCATIONS NEAR THE COAST. THE PASSAGE OF THE COLD FRONT EARLY ON THURSDAY SHOULD CAUSE MAXIMUM TEMPERATURES TO DROP BACK AROUND 80 DEGREES FOR THURSDAY AND FRIDAY. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. HIGH PRESSURE TO THE WEST WILL GRADUALLY BUILD INTO THE REGION LATE TODAY THROUGH SUNDAY. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AND BEYOND, WITH NOT MUCH MORE THAN SOME SCATTERED CUMULUS. THE MAIN AVIATION CONCERN THROUGH THIS EVENING IS GUSTY W TO NW WINDS DUE TO A TIGHT PRESSURE GRADIENT BETWEEN THE DEPARTING TROPICAL STORM EARL, AND THE BUILDING HIGH PRESSURE. WIND SPEEDS HAVE ALREADY INCREASED THIS MORNING BEHIND THE FRONT, AND WILL CONTINUE THROUGH EARLY EVENING. WIND GUSTS UP TO 30 KTS ARE LIKELY. AFTER SUNSET, WIND SPEEDS WILL DROP TO 10 KT OR LESS AND SKC IS ANTICIPATED. OUTLOOK... GOOD VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE HOLIDAY WEEKEND AS HIGH PRESSURE DOMINATES THE WX PATN. && .MARINE... TROPICAL STORM EARL WILL CONTINUE ITS NORTHEAST TREK FROM NEW ENG TO THE CANADIAN MARITIMES. HIGH PRESSURE WILL GRADUALLY BUILD IN AND REMAIN OVER THE REGION THROUGH THE EARLY PART OF NEXT WEEK. SEAS WILL CONTINUE TO DECREASE AS EARL LOSES ITS GRIP ON THE AREA. HOWEVER, FROPA AND THEN THE TIGHT PRESSURE GRADIENT BTWN EARL AND THE BUILDING HIGH WILL MAKE FOR GUSTY W TO NW WINDS. GUSTS TO 30 KT CAN BE EXPECTED. LATEST GUIDANCE INDICATES THAT THE WINDS COULD REMAIN GUSTY THROUGH SUNSET, SO WILL EXTEND THE SCA UNTIL 05/00Z ON ALL OF THE AREA WATERS. AFTER THE WINDS DECREASE TONIGHT, EXPECT MUCH IMPROVED AND RELATIVELY TRANQUIL CONDS ON THE AREA WATERS INTO EARLY NEXT WEEK. && .FIRE WEATHER... AFTER CONSULTING WITH MARYLAND FOREST OFFICIALS...HAVE EXPANDED THE RED FLAG WARNING TO INCLUDE EASTERN MARYLAND. ALSO INCLUDED THE REST OF SOUTHEAST PENNSYLVANIA AND DELAWARE. ALL OF THE ABOVE AREAS SHOULD REACH CRITERIA THIS AFTERNOON. 1200 UTC SOUNDINGS SHOW THE POTENTIAL FOR 35 MPH WIND GUSTS...AS WELL AS MIXING DRY AIR FROM NEAR 850 MB TO THE SURFACE. THIS WILL RESULT IN DEW POINTS DROPPING INTO THE LOWER TO MID 40S (WHICH IS OCCURRING IN SOME PLACES ALREADY). LEFT OUT THE LEHIGH VALLEY AND NORTHWEST NEW JERSEY...WHERE DEVELOPING CLOUDINESS SHOULD KEEP MINIMUM RELATIVE HUMIDITY VALUES ABOVE 30 PERCENT. && .RIP CURRENTS... SINCE THE SEAS ARE STILL RUNNING ON THE HIGH SIDE IN THE SURF ZONE ALONG WITH THEM BEING MORE OF A LONGER PERIOD, THE RIP CURRENT RISK IS A SOLID MODERATE RATING TODAY. GIVEN THIS IS A HOLIDAY WEEKEND, WE OPTED TO ISSUE A COASTAL HAZARD MESSAGE /CFWPHI/ PRODUCT TO HIGHLIGHT THE MODERATE RISK. CONDITIONS MAY IMPROVE SOME TOWARD EVENING AND SHOULD BE MUCH IMPROVED FOR THE REMAINDER OF THE LABOR DAY WEEKEND AS THE SEAS AND WINDS LOWER. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ067>071. NJ...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR NJZ012>027. DE...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR DEZ001>004. MD...RED FLAG WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR MDZ008-012- 015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...DRAG NEAR TERM...HAYES SHORT TERM...DRAG LONG TERM...IOVINO AVIATION...NIERENBERG MARINE...NIERENBERG FIRE WEATHER...DRAG/HAYES RIP CURRENTS...GORSE 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