Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 120857 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 357 AM EST FRI FEB 12 2016 .SYNOPSIS...
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AN AREA OF LOW PRESSURE WILL REMAIN TO OUR SOUTHEAST TODAY, WHILE ANOTHER MOVES OUT OF THE GREAT LAKES AND INTO NEW ENGLAND TONIGHT INTO SATURDAY MORNING, PULLING A COLD FRONT ACROSS OUR AREA. BITTER COLD AIR WILL MOVE INTO THE AREA OVER THE WEEKEND, BEFORE HIGH PRESSURE BUILDS ACROSS THE AREA SUNDAY. THIS HIGH WILL BUILD OFFSHORE MONDAY. AN AREA OF LOW PRESSURE WILL MOVE UP THE EAST COAST AND AFFECT OUR AREA MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL RETURN FOR THURSDAY INTO FRIDAY.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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MID AND UPPER LEVEL LOW DIGS SOUTHEAST FROM CANADA, THROUGH THE DAY. IN RESPONSE, SHOULD SEE THE SURFACE LOW IN THE GREAT LAKES REGION INTENSIFY AS IT LIFTS NORTHEAST. THOUGH THIS WOULD SUGGEST A MID LEVEL WARM AIR ADVECTION PATTERN. HOWEVER, WITH SURFACE WINDS STILL NORTHWESTERLY, ALBEIT CONSIDERABLY LIGHTER THAN YESTERDAY, DO NOT EXPECT THIS TO TRANSLATE INTO HIGHER MAX TEMPS AS COMPARED TO YESTERDAY. IF ANYTHING, TEMPS WILL LIKELY BE A DEGREE OR TWO LOWER THAN YESTERDAY. SNOW...LAPSE RATES AREN`T QUITE AS IMPRESSIVE AS WHAT WE SAW YESTERDAY WHEN THERE WERE SCATTERED SNOW SHOWERS. HOWEVER, WHAT THIS PATTERN LACKS IN LAPSE RATES, IT LOOKS TO MAKE UP FOR IN LIFT ASSOCIATED WITH THE APPROACHING MID AND UPPER LEVEL TROUGH. THUS, THERE SHOULD BE A CHANCE FOR SNOW SHOWERS ACROSS THE REGION, WITH HIGHER CHANCES TOWARDS THE POCONOS.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
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COULD SEE SNOW SHOWERS LINGER THROUGH MIDNIGHT AS THE SURFACE TROUGH CROSSES THE REGION. CONTINUED COLD AIR ADVECTION WILL MEAN ANOTHER VERY CHILLY NIGHT, WITH LOWS GENERALLY IN THE TEENS (EXCEPT IN THE POCONOS AND NW NJ, WHERE SINGLE DIGITS ARE POSSIBLE ESPECIALLY OVER THE HIGHER TERRAIN). HOWEVER, WINDS SHOULD BE LIGHT, SO AT THIS POINT IT DOESN`T LOOK LIKE ANYONE WILL REACH WIND CHILL ADVISORY CRITERIA. THE EXCEPTION TO THIS IS IN THE POCONOS, WHICH COULD COME CLOSE TO ADVISORY CRITERIA EARLY SATURDAY MORNING. HOWEVER, TO KEEP THINGS SIMPLE, WE WILL JUST MENTION THE POTENTIAL WITH THE WIND CHILL WARNING WHICH WILL BE STARTING SATURDAY MORNING.
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&& .LONG TERM /SATURDAY THROUGH THURSDAY/...
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THE MAIN FOCUS ON THE EXTENDED FORECAST IS THE BITTER COLD AFFECTING THE AREA THIS WEEKEND. SUB-ZERO TEMPERATURES AND WIND CHILLS WILL AFFECT THE AREA SATURDAY THROUGH SUNDAY. ON SATURDAY, AN AREA OF LOW PRESSURE TO THE NORTH WILL WEAKEN AS IT MOVES INTO NORTHERN NEW ENGLAND, WHILE THE LOW OFF THE COAST STRENGTHENS. AN ARCTIC FRONT WILL MOVE ACROSS THE AREA DURING THE DAY SATURDAY, WHICH WILL USHER IN MUCH COLDER AIR. IN FACT, TEMPERATURES WILL LIKELY FALL THROUGH THE DAY SATURDAY. THERE WILL ALSO BE A CHANCE FOR ISOLATED SNOW SHOWERS ACROSS THE AREA AS THERE WILL BE FAIRLY STEEP LOW-MID LEVEL LAPSE RATES COMBINED WITH ENHANCE LOW-MID LEVEL MOISTURE WITHIN THE NORTHWEST FLOW. SPEAKING THE NORTHWEST FLOW, WINDS SATURDAY WILL LIKELY GUST 35-40 MPH, WITH SOME AREA APPROACHING ADVISORY LEVELS; WE`VE HELD OF ON ANY WIND ADVISORY AT THIS TIME. ANY SNOW SHOWERS SHOULD END BY THE EVENING, BUT THE WIND WILL REMAIN STRONG THROUGH THE NIGHT. ALONG WITH THE WINDS, THE BITTER AIR WILL CONTINUE TO PUSH INTO THE AREA. THE WIND CHILL WARNING ACROSS THE POCONOS WILL CONTINUE THROUGH THE NIGHT. FOR THE REMAINDER OF THE AREA, SUB-ZERO WIND CHILLS WILL OCCUR, WITH MOST AREAS REACHING INTO -5 TO -15 RANGE. SUNDAY WILL REMAIN COLD, ALTHOUGH WINDS WILL WEAKEN SOME DURING THE DAY AS HIGH PRESSURE BEGINS TO BUILD ACROSS THE AREA. SUNDAY INTO SUNDAY NIGHT WILL REMAIN PRECIPITATION FREE AS THE AIR MASS WILL BE QUITE DRY; ALTHOUGH MOISTURE BEGINS TO INCREASE SUNDAY NIGHT AS HIGH PRESSURE BUILDS OFFSHORE. HOWEVER, AS WE GO INTO MONDAY, MOISTURE CONTINUES TO INCREASE ACROSS THE AREA WITHIN THE RETURN FLOW WITH HIGH PRESSURE OFFSHORE. A LOW PRESSURE SYSTEM WILL BE STRENGTHENING ALONG THE GULF STATES MONDAY, WHILE A WARM FRONT BEGINS TO LIFT NORTHWARD TOWARD OUR AREA. OVERRUNNING PRECIPITATION MAY BEGIN AFFECTING THE AREA STARTING MONDAY, AND WITH TEMPERATURES BEING COLD ENOUGH, PRECIPITATION WILL LIKELY START OUT AS SNOW FOR MUCH OF THE AREA. THE LOW WILL CONTINUE TO STRENGTHEN MONDAY NIGHT, AND MAKE ITS WAY INTO OUR AREA TUESDAY. WARMER AIR WILL MOVE INTO THE AREA AS THE LOW MAKES ITS WAY NORTHWARD, SO MOST AREAS ARE EXPECTED TO TURN TO RAIN DURING THE DAY TUESDAY. AS THE LOW LIFTS TO OUR NORTH TUESDAY NIGHT, WE COULD HAVE SOME WRAP AROUND PRECIPITATION ON THE BACKSIDE, WHICH COULD TURN BACK TO SNOW. NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY AND WEDNESDAY NIGHT AS THE LOW LIFTS WELL TO OUR NORTH, AND HIGH PRESSURE BUILDS TO OUR WEST.SOME SHOWERS ARE POSSIBLE ACROSS THE AREA WITHIN THE NORTHWEST FLOW.THE PRECIPITATION COULD CHANGE TO RAIN FOR MANY AREAS DURING THE DAY AS TEMPERATURES WILL REMAIN WARM. HIGH PRESSURE WILL BUILD ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT WHICH WILL ALLOW FOR DRY CONDITIONS TO RETURN THE AREA.
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&& .AVIATION /09Z FRIDAY THROUGH TUESDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. PREDOMINANTLY VFR CONDITIONS ARE EXPECTED THROUGH LATE THIS AFTERNOON. BY 21Z, CHANCES FOR SNOW SHOWERS INCREASE ACROSS THE REGION LASTING THROUGH THE EVENING HOURS. WITH THE SNOW SHOWERS, EXPECT MVFR, AND POSSIBLY BRIEF IFR CONDITIONS. AT THIS POINT, EXPECT THE HIGHEST RISK OF SNOW SHOWERS TO INCLUDE KABE, KRDG, KTTN, KPNE, AND KPHL, ALTHOUGH THERE IS A SMALL CHANCE AT THE OTHER TAF SITES AS WELL. SNOW CHANCES SHOULD DECREASE CONSIDERABLY AFTER 06Z. HOWEVER, MVFR CEILINGS MAY PERSIST BEYOND THAT. OUTLOOK... SATURDAY...GENERALLY VFR CIGS. ISOLATED SNOW SHOWERS POSSIBLE, WHICH COULD REDUCE CIGS/VSBYS TEMPORARILY. NORTHWEST WINDS INCREASING SATURDAY TO 15-25 KNOTS WITH GUSTS UP TO 40 KNOTS. SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS 10 TO 25 KNOTS WITH GUSTS 30-35 KNOTS EARLY, DIMINISHING SOME OVERNIGHT INTO SUNDAY. GUSTS STILL 20-25 KNOTS OVERNIGHT INTO EARLY SUNDAY. MONDAY-MONDAY NIGHT...DEGRADING CONDITIONS WITH MVFR/IFR LIKELY THROUGH THE DAY MONDAY INTO MONDAY NIGHT. SNOW POSSIBLY BEGINNING MONDAY FOR MANY AREAS, POSSIBLY MIXING WITH RAIN AT TIMES FOR SOME AREAS. TUESDAY...MVFR/IFR CONDITIONS CONTINUING INTO TUESDAY. PRECIPITATION MAY CHANGE OVER TO RAIN FOR MANY AREAS DURING THE DAY.
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&& .MARINE...
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SHOULD SEE A LULL IN THE WINDS AND SEAS TODAY AND THROUGH THE FIRST HALF OF THE NIGHT BUT EXPECT WINDS TO INCREASE CONSIDERABLY AFTER MIDNIGHT, REACHING GALE FORCE ON ALL THE WATERS BEFORE DAWN. WITH THE INCREASING WINDS, ALSO EXPECT FREEZING SPRAY RATES TO INCREASE, SO HAVE ISSUED A FREEZING SPRAY ADVISORY FOR THE SAME PERIOD AS WELL. OUTLOOK... SATURDAY-SATURDAY NIGHT...GALE WARNING CONTINUES WITH STRONG NORTHWEST FLOW ACROSS THE AREA. FREEZING SPRAY ADVISORY REMAINS IN EFFECT AS VERY COLD AIR AND STRONG WINDS WILL LEAD TO AT LEAST MODERATE FREEZING SPRAY. SUNDAY-SUNDAY NIGHT...GALE WARNING AND FREEZING SPRAY ADVISORY CONTINUE INTO SUNDAY MORNING. HOWEVER, WINDS WILL DIMINISH THROUGH THE DAY AND SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. MONDAY-TUESDAY...AT LEAST SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY RETURN TO THE AREA AS STRONG LOW PRESSURE MOVES UP THE EAST COAST MONDAY INTO TUESDAY.
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&& .CLIMATE... 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 THROUGH FRIDAY NIGHT. PLEASE NOTE... GUIDANCE IN PART IS BEING CLIMO BIASED HIGHER THAN WHAT THE ONCOMING GFS/ECMWF LITERAL AIRMASS AND 2M TEMPS ARE INDICATING FOR SUNDAY MORNING. TEMPS SUNDAY MORNING IN THE URBAN AREAS SHOULD BE ABOUT 25 COLDER THAN NORMAL. THAT MEANS GUIDANCE TEMPS FOR PHL OF 5 AND 6 DEGREES APPEAR TOO WARM...ESPECIALLY WITH A NORMAL PHILADELPHIA LOW ON SUNDAY OF 28. HAVE SEEN THE 12Z/11 2M TEMPS FOR PHL...1 ABOVE RANGING DOWN TO -11 AT KMPO AND AM LIKING THOSE VALUES AS WITHIN 2F OF THE UPCOMING REALITY. RECORD LOW MAX`S CAN ONLY OCCUR FOR THIS EVENT ON SUNDAY THE 14TH, IF THEN. THOSE HAVE BEEN ADDED RECENTLY BELOW. SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ----RER LOW MAX ---------------------- -------------------- ABE 8 -1 IN 1979 14-1979 ACY 10 -6 IN 1979 13-1979 PHL 12 +2 IN 1979 14-1979 ILG 12 -4 IN 1979 13-1979 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. && .PHI WATCHES/WARNINGS/ADVISORIES...
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PA...WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR PAZ054-055. NJ...WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR NJZ001. DE...NONE. MD...NONE. MARINE...FREEZING SPRAY ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY FOR ANZ430-431-450>455. GALE WARNING FROM 4 AM SATURDAY TO 10 AM EST SUNDAY FOR ANZ430- 431-450>455.
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&& $$ SYNOPSIS...ROBERTSON NEAR TERM...JOHNSON SHORT TERM...JOHNSON LONG TERM...ROBERTSON AVIATION...JOHNSON/ROBERTSON MARINE...JOHNSON/ROBERTSON CLIMATE...

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