Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 110245 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 945 PM EST WED FEB 10 2016 .SYNOPSIS...
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LOW PRESSURE OVER THE SAINT LAWRENCE VALLEY WILL MOVE INTO THE BAY OF FUNDY THURSDAY, WHILE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY MOVES INTO THE MIDDLE ATLANTIC ON FRIDAY. A STRONG ARCTIC COLD FRONT WILL MOVE THROUGH OUR REGION ON SATURDAY, SWEEPING LOW PRESSURE OVER THE OUTER BANKS OF NORTH CAROLINA WELL OUT TO SEA. HIGH PRESSURE WILL MOVE INTO OUR AREA FROM THE OHIO VALLEY ON SUNDAY, AND MOVE OFF THE MID ATLANTIC COAST ON MONDAY. TWO STORM SYSTEMS ARE EXPECTED TO JOIN FORCES OVER THE MIDDLE ATLANTIC, AND MOVE UP THE EAST COAST ON TUESDAY AND WEDNESDAY.
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&& .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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THE SKY WAS MOSTLY CLOUDY OVER OUR REGION THIS EVENING. AN AREA OF SNOW SHOWERS WAS PASSING ACROSS THE MIDDLE DELMARVA PENINSULA AND IT SHOULD BE OFF THE COAST BY MIDNIGHT. A LIGHT COATING OF SNOW WILL ACCUMULATE ALONG THE SOUTHERN EDGE OF DELAWARE. A NEGATIVE TILT MID LEVEL TROUGH IS FORECAST TO PASS OVER OUR REGION IN THE MIDNIGHT TO 400 AM TIME FRAME. THE FEATURE MAY TOUCH OFF ADDITIONAL SNOW SHOWERS AND FLURRIES, MAINLY ALONG AND TO THE NORTH OF THE INTERSTATE 78 CORRIDOR. SNOWFALL AMOUNTS WILL BE LIGHT, GENERALLY UP TO A FEW TENTHS OF AN INCH. A WEST WIND WILL FAVOR THE 10 TO 15 MPH RANGE OVERNIGHT. TEMPERATURES ARE FORECAST TO FALL INTO THE TEENS UP NORTH AND INTO THE LOWER AND MIDDLE 20S ELSEWHERE.
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&& .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
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PARTLY SUNNY AND BRISK. SCATTERED BRIEF SNOW SHOWERS OR FLURRIES, MAINLY I-78 NWWD WHERE VERY UNSTABLE 925-700MB LAPSE RATES AND SEMBLANCE OF A TROUGH. BTV SNOW SQUALL PARAMETER PREDICTION TOOL HAS SUPPORTIVE INDICATION. GUSTY WEST NORTHWEST WINDS TO 35 MPH 11 AM TO 3 PM. MAX TEMPS ABOUT 10F BELOW NORMAL.
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&& .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
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THE MAIN CONCERN IS A PERIOD OF WIND-DRIVEN MUCH BELOW NORMAL TEMPERATURES, THE COLDEST OF THE SEASON SO FAR, SATURDAY INTO SUNDAY WITH INCREASING CONFIDENCE OF DANGEROUSLY LOW WIND CHILLS. OTHERWISE, THE FRIDAY THROUGH WEDNESDAY TIME FRAME IS GENERALLY EXPECTED TO BE UNSETTLED, WITH A CYCLONIC FLOW ALOFT. FRIDAY AND FRIDAY NIGHT, CLOUDS WILL INCREASE IN ADVANCE OF TWO SEPARATE SHORT WAVES, ONE OVER THE GREAT LAKES AND ANOTHER OVER THE MID ATLANTIC. THESE ARE EXPECTED TO REMAIN LARGELY SEPARATE, WITH ONLY A CHANCE OF SNOW SHOWERS IN THE FORECAST FOR THE FRIDAY NIGHT PORTION OF THE FORECAST. SATURDAY AND SUNDAY, WITH THE PASSAGE OF AN ARCTIC COLD FRONT SATURDAY MORNING, MUCH BELOW TEMPERATURES ARE FORECAST. DURING THIS TIME FRAME, 850 MB TEMPERATURES WILL PLUNGE TO AROUND -25C AT KPHL! WE ALSO EXPECT NORTHWEST WINDS OF 15 TO 25 MPH WITH THE POTENTIAL FOR GUSTS TO 40 MPH SATURDAY INTO SATURDAY EVENING, TAPERING DOWN 10 TO 20 MPH WITH CONTINUED GUSTINESS THROUGH SUNDAY MORNING. LOW TEMPERATURES OF ZERO TO 10 BELOW ZERO ARE FORECAST FOR THE ENTIRE REGION, WHICH LEADS TO WIND CHILL VALUES DANGEROUSLY COLD IN THE 10 BELOW TO 25 BELOW ZERO RANGE SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY, TEMPERATURES MODERATE QUICKLY, RETURNING TO NEAR NORMAL ON TUESDAY. THE MAIN UNCERTAINTY IS THE TRACK OF LOW PRESSURE ORGANIZING NEAR THE EAST COAST, WITH THE 12Z ECMWF NEAR THE APPALACHIANS AND THE GFS MORE OFFSHORE. IN ANY EVENT, THIS WILL BE AN UNSETTLED PERIOD OF WEATHER WITH THE POTENTIAL FOR BOTH SNOW AND RAIN.
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&& .AVIATION /03Z THURSDAY THROUGH MONDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD, WITH ONE EXCEPTION. SCATTERED SNOW SHOWERS MAY OCCUR AROUND KRDG, KABE AND KTTN IN THE 0400Z TO 0800Z TIME FRAME. THERE IS THE POTENTIAL FOR A BRIEF PERIOD OF MVFR CONDITIONS AT THOSE LOCATIONS. THE WIND WILL FAVOR THE WEST AT 8 TO 12 KNOTS OVERNIGHT. WIND SPEEDS ARE FORECAST TO INCREASE TO 15 TO 20 KNOTS ON THURSDAY WITH GUSTS NEAR 30 KNOTS. OUTLOOK... THURSDAY NIGHT...VFR CONDITIONS. FRIDAY AND FRIDAY NIGHT...PREDOMINANTLY VFR. MVFR POSSIBLE IN SCATTERED SNOW SHOWERS. SATURDAY AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS 15 TO 25 KNOTS WITH GUSTS TO 30 KNOTS POSSIBLE, MAINLY SATURDAY AND SATURDAY NIGHT. MONDAY...VFR CONDITIONS. MVFR POSSIBLE IN RAIN OR SNOW SHOWERS.
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&& .MARINE...
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SST`S ARE AROUND 5 TO 8F WARMER THAN NORMAL FOR FEBRUARY AND THESE WATER TEMPERATURES WARMED ABOUT 5 DEGREES FROM THE MID JANUARY WATER TEMPERATURE TUMBLE. THE REASONING FOR THE WARMING, EVEN IN DE BAY IS NOT WELL UNDERSTOOD BY MYSELF BUT IT HAS OCCURRED AND I THINK BECOMES A MORE IMPORTANT PLAYER IN AIDING MOMENTUM TRANSFER THROUGH THESE COLD AIR ADVECTION EPISODES BY STEEPENING THE BOUNDARY LAYER LAPSE RATE. GLW CONTD. FUNNELING AND EARLIER START TO THE DEEPENING BOUNDARY LAYER MIXING FOR DE BAY SHOULD PERMIT A FEW GUSTS TO 35 KT VCNTY SJS, BWINE...LWS SOMETIME BETWEEN 1 AM AND 4 AM THURSDAY. CONFIDENCE ON THE STARTING TIME OF GALE GUSTS THERE IS AVERAGE. THEREAFTER...WNW GALE GUSTS SPREAD TO THE ATLANTIC WATERS OF NJ AND DE DURING THE MORNING, BECOMING MOST PERSISTENT THURSDAY AFTN/EVE WHEN A FEW GUSTS TO 40 KT ARE EXPECTED. HIGH CONFIDENCE. WE HAVE NO WIND DATA AT 44009 SO TO VERIFY, WE HAVE 44065 AND WE USE MULTIPLE COASTAL WIND OBSERVATIONS ADJACENT THE WATER INCLUDING NOS/USGS/WEATHERFLOW MESONET PLATFORMS. OUTLOOK... THURSDAY NIGHT...GALE WARNING IN EFFECT THROUGH 6Z...FOLLOWED BY SMALL CRAFT ADVISORY /SCA/ WINDS THROUGH EARLY FRIDAY MORNING. WINDS WILL INCREASE AGAIN TO SCA LEVELS FRIDAY NIGHT AHEAD OF AN ARCTIC COLD FRONT. WINDS INCREASE TO GALE FORCE LATE FRIDAY NIGHT AND MAY MAINTAIN GALES THROUGH SATURDAY NIGHT. A SCA MAY BE NEEDED ON SUNDAY, WITH SUB-SCA ON MONDAY.
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&& .CLIMATE...
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NEAR RECORD COLD IS EXPECTED FOR PORTIONS OF OUR AREA SUNDAY MORNING AND BY FAR THE COLDEST AIR OF THE SEASON SO FAR. ANTICIPATING TEMPS THROUGHOUT OUR FORECAST AREA WITHIN SEVERAL DEGREES OF ZERO (WIND IS THE EQUALIZER) ANYTIME FROM MIDNIGHT THROUGH 8 AM SUNDAY EXCEPT COLDER KMPO (NEAR -12F). THIS HAS BEEN ADVERTISED BY THE GFS/ECMWF 2M TEMPS CYCLICALLY SINCE AT LEAST THE 00Z/7 OPERATIONAL CYCLES. THEREFORE, BEST CHANCE FOR RECORD EQUALING OR EXCEEDING FOR VALENTINES DAY THE 14TH WOULD BE KABE, KTTN, KPHL AND KMPO. SNOW COVER MAY HELP A BIT I-95 NORTHWESTWARD...AND WE`LL SEE WHERE WE ARE WITH SNOW COVER BY THURSDAY EVENING. NEW DUSTINGS APPEAR ON THE WAY THE NEXT 30 HOURS. SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ---- ---------------------- -------------------- ABE 8 -1 IN 1979 ACY 10 -6 IN 1979 PHL 12 +2 IN 1979 ILG 12 -4 IN 1979 RDG 10 -4 IN 1983 TTN 9 0 IN 1916 GED 13 -7 IN 1979 MPO -1 -12 IN 1970 SO, THIS WILL BE WIND DRIVEN COLD WITH MANY AREAS EXPERIENCING WIND CHILL VALUES OF 15 TO 25 BELOW ZERO...POSSIBLY 30 BELOW IN THE HILLS AND MOUNTAINS OF NORTHWEST NEW JERSEY AND NORTHEAST PENNSYLVANIA.
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&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ450>455. GALE WARNING FROM 6 AM THURSDAY TO 1 AM EST FRIDAY FOR ANZ450>455. GALE WARNING FROM 1 AM TO 11 PM EST THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...FRANCK NEAR TERM...IOVINO SHORT TERM...DRAG LONG TERM...FRANCK AVIATION...FRANCK/IOVINO MARINE...DRAG/FRANCK CLIMATE...DRAG

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