Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 221116 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 616 AM EST SAT NOV 22 2014 .SYNOPSIS... STRONG HIGH PRESSURE WILL REMAIN OVER THE MID ATLANTIC STATES TODAY BEFORE MOVING OFFSHORE ON SUNDAY. AS THE HIGH MOVES EASTWARD, THE SOUTHWESTERLY FLOW AROUND IT WILL BRING A WARMING TREND TO THE AREA. LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS WILL MOVE NORTHEASTWARD ON SUNDAY AND BRING A WARM FRONT THROUGH THE REGION SUNDAY NIGHT. THE LOW WILL BE NEAR THE GREAT LAKES BY MONDAY MORNING AND AS IT MOVES INTO EASTERN CANADA BY TUESDAY, ITS ASSOCIATED COLD FRONT WILL CROSS THE AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTH FOR MONDAY NIGHT AND TUESDAY. THEN, AN AREA OF LOW PRESSURE MAY DEVELOP OFF THE ATLANTIC COAST FOR WEDNESDAY AND WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE SURFACE HIGH WILL SHIFT FURTHER SOUTHEAST, LEAVING THE REGION WITH SOUTHERLY RETURN FLOW. AS SUCH, EXPECT MOIST AND WARM AIR ADVECTION THROUGH THE DAY TODAY. THUS, HIGHS TODAY SHOULD BE AROUND 5 DEGREES HIGHER THAN YESTERDAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THINGS GET A BIT MORE INTERESTING TONIGHT AS MID LEVEL SHORT WAVE TROUGH MOVES OVER THE NORTHEASTERN U.S.. BOTH THE GFS AND NAM SHOW THE BEST SYNOPTIC LIFT (AS EVIDENCED BY 500 MB Q VECTOR CONVERGENCE AND POSITIVE PRESSURE ADVECTION ON THE 1.5 PV SURFACE) STAYING JUST NORTH OF OUR REGION. HOWEVER, GIVEN HOW CLOSE THE LIFT IS, AND GIVEN THAT THERE COULD ALSO BE SOME OROGRAPHIC LIFT, HAVE SLIGHTLY INCREASED POPS IN THE POCONOS, LEHIGH VALLEY, AND NW NJ. BUT IT STILL SEEMS LIKE AN UNLIKELY EVENT FOR OUR REGION, SO MOST OF THE REGION HAS POPS AT OR BELOW 30 PERCENT. IF THERE IS ANY PRECIPITATION IN OUR AREA, IT WILL BE EITHER IN THE FORM OF RAIN OR FREEZING RAIN (DEPENDING ON SURFACE TEMPERATURE). MODEL SOUNDINGS SHOW A ROBUST AND DEEP WARM LAYER. WHILE THERE COULD BE SOME SEEDER FEEDER CIRRUS CLOUDS PROPAGATING OVERHEAD, WITH THE MELTING LAYER AROUND 8000 FT MSL, ANY ICE CRYSTALS WOULD MELT THROUGH THE WARM LAYER. BECAUSE OF THE CONTINUED WARM AIR ADVECTION EVEN AT THE SURFACE, SEE VERY FEW LOCATIONS DROPPING BELOW FREEZING BEFORE THE WINDOW OF OPPORTUNITY FOR PRECIPITATION CLOSES. SINCE TOO, THE CHANCE OF PRECIPITATION IS VERY SMALL AT THIS TIME, WILL NOT ISSUE A FREEZING RAIN ADVISORY, BUT WILL CONTINUE TO MENTION THE POTENTIAL IN THE HWO. && .LONG TERM /SUNDAY THROUGH FRIDAY/...
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A NICE WARMING TREND IS IN STORE AT THE START OF THE EXTENDED PD AS HIGH PRES MOVES OFFSHORE AND STRONG SWLY FLOW DEVELOPS OVER THE AREA. THEN, LOW PRES WILL TAKE SHAPE OVER THE SRN PLAINS AND BEGIN TO MOVE NEWD. THE WMFNT ASSOCD WITH THIS LOW WILL MOVE THRU THE REGION SUN NIGHT AS THE LOW REALLY INTENSIFIES OVER THE MIDSECTION OF THE NATION. BASED ON THE LATEST GUID MOVG THE PRECIP IN SLOWER, HAVE REMOVED POPS FROM THE SUNDAY DAYTIME HOURS. THE BEST WAA IS SUN NIGHT AND THIS IS THE WETTEST PERIOD WITH RAIN, SOME HEAVY AT TIMES. WE GET DRY SLOTTED LATER MON AND IN THE WARM SECTOR, TEMPS WILL SKYROCKET AND COULD REACH RECORD VALUES IN SOME LOCATIONS, THEN THE COLD FRONT WILL CROSS THE REGION MONDAY NIGHT, WITH ANOTHER CHC OF PRECIP MON EVE BEFORE HIGH PRES BUILD BACK IN FOR LATER MON NIGHT THRU TUE NIGHT. THEN, ALL EYES TURN TO THE POTENTIAL FOR A COASTAL LOW DEVELOPING AROUND WED. MODEL SOLNS ARE ALL OVER THE PLACE AND CONFIDENCE IS MUCH BELOW AVERAGE ATTM. THE CMC IS WELL OFFSHORE WITH VIRTUALLY NO IMPACT TO OUR REGION. THE GFS INDICATES THE MOST IMPACT FOR OUR SRN AND ERN LOCATIONS WED INTO WED NIGHT BEFORE THE LOW PULLS AWAY ON THANKSGIVING, BRINGING A DRY HOLIDAY. THE ECMWF HAS THE STRONGEST AND MOST WWD SOLN AND WOULD BRING A MOSTLY WET AND WINDY PERIOD FROM WED INTO WED NIGHT. IT HAS SOME SUPPORT FROM THE UKMET. ANY WINTRY PRECIP WOULD BE CONFINED TO NRN AAND WRN AREAS AT THE ONSET AND THE END. WITH THE POTENTIAL FOR SIGNIFICANT IMPACT DUE TO HOLIDAY TRAVEL AND ONE OF THE BUSIEST AIR TRAVEL DAYS OF THE YEAR, THIS SYS WILL CONTINUE TO BE WATCHED AND COULD END UP BEING NOTHING OR SOMETHING SIGNIFICANT. THE ECMWF MADE A DECENT WWD SHIFT FROM 21/12Z TO 22/00Z, THE GFS DID NOT. AFTER THIS STORMS MOVES BY WHETHER FAR OFFSHORE OR CLOSE TO THE COAST, ANOTHER WK CDFNT MAY BRING SOME PRECIP ERLY FRI. TEMPS WILL START OFF FAIRLY WARM ON SUNDAY, REACH THEIR ZENITH ON MON, WITH NEAR RECORD WARMTH, THEN STILL BE NR NRML ON TUE BEFORE TAKING A NOSE DIVE THRU THE REMAINDER OF THE WEEK.
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&& .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. AFTER 18Z, CLOUDS WILL INCREASE, FIRST HIGH CIRRUS CLOUDS, THEN MID LEVEL CLOUDS (AT OR ABOVE 5000 FT AGL) WILL MOVE IN CLOSER TO 00Z. THERE IS ALSO A SMALL CHANCE OF -RA OR -FZRA GENERALLY N AND W OF THE I95 CORRIDOR (INCLUDING KABE AND KRDG) BETWEEN 00 AND 09Z. HOWEVER, AT KRDG AND KABE IT IS ONLY A 20 PERCENT CHANCE, AND ANY PRECIPITATION SHOULD BE -RA. OUTLOOK... SUN...VFR, WITH INCREASING AND LOWERING CLOUDS BY EVENING. HIGH CONFIDENCE. SUN NIGHT THROUGH EARLY MON...VERY POOR FLYING CONDS WITH MVFR EXPECTED AND IFR PSBL IF NOT PROBABLE IN RAIN. RAIN COULD BE HVY AT TIMES. E TO SE WIND COULD GUST IN THE 20 TO 25 KT RANGE. MDT TO HIGH CONFIDENCE. MON AND MON NIGHT...IMPROVING CONDS BUT STILL SOME MVFR PSBL IN LINGERING SHWRS. CFP/WSFHT MON EVE. VFR BY EVE IF NOT SOONER. LOW TO MDT CONFIDENCE. WEDNESDAY...MUCH UNCERTAINTY DEPENDING ON THE TRACK OF A COASTAL LOW. COULD BE VFR IF LOW IS FAR ENOUGH EAST OR MVFR/IFR IN RAIN AND WIND IF LOW IS FAR ENOUGH W. BEST CHC FOR VFR IS WRN AIRPORTS. BEST CHC FOR DEGRADED CONDS IS ERN AIRPORTS. CONFIDENCE VERY LOW.
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&& .MARINE... WINDS AND SEAS WILL INCREASE BY MID DAY TODAY AS THE HIGH SHIFTS FURTHER SOUTHEAST. WIND GUSTS OF 25 TO 30 KT WILL BE POSSIBLE ON THE ATLANTIC COASTAL WATERS THIS AFTERNOON THROUGH VERY EARLY SUNDAY MORNING. WAVE HEIGHTS UP TO 5 FT ARE EXPECTED IN THE ATLANTIC, AND MAY BE SLOWER TO DECREASE SUNDAY MORNING. FOR NOW HAVE ISSUED THE SMALL CRAFT ADVISORY FROM NOON TODAY THROUGH 6 AM SUNDAY MORNING. OUTLOOK... SUN...NO MARINE HEADLINES ANTICIPATED. SUN NIGHT THROUGH MON...SCA CONDS ARE EXPECTED AND GALES ARE PSBL IF NOT PROBABLE INTO ERLY MON AS STRONG LOW PRES IMPACTS THE WATERS. MON NIGHT INTO TUE....BACK END SCA CONDS AS SEAS AND WIND SUBSIDE SLOWLY. WED...NO MARINE HEADLINES ANTICIPATED. && .CLIMATE...
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HERE ARE THE RECORD LOWS FOR 11/22. ATLANTIC CITY 12 SET IN 1879 PHILADELPHIA 14 SET IN 1880 WILMINGTON 17 SET IN 1964 ALLENTOWN 17 SET IN 1969 AND 1964 *HAS ALREADY BEEN BROKEN AS ALLENTOWN HAS HAD A LOW SO FAR OF 16* TRENTON 15 SET IN 1880 GEORGETOWN 16 SET IN 1987 READING 16 SET IN 1969 MOUNT POCONO 5 SET IN 1969 SO FAR ONLY ALLENTOWN HAS SET A RECORD LOW. HOWEVER A FEW SITES REMAIN WITHIN A FEW DEGREES OF THEIR RECORDS SO WE WILL CONTINUE TO MONITOR THE TEMPERATURES THROUGH THE EARLY MORNING HOURS BEFORE SENDING OUT ANY RECORD EVENT REPORTS.
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&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EST SUNDAY FOR ANZ450>455. && $$ SYNOPSIS...NIERENBERG NEAR TERM...JOHNSON SHORT TERM...JOHNSON LONG TERM...NIERENBERG AVIATION...JOHNSON/NIERENBERG MARINE...JOHNSON/NIERENBERG CLIMATE...JOHNSON

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