Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 191036 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 636 AM EDT SUN OCT 19 2014 .SYNOPSIS... HIGH PRESSURE LOCATED OVER THE OHIO VALLEY EARLY TODAY WILL MOVE EAST AND CREST OVER THE MIDDLE ATLANTIC REGION MONDAY. THE HIGH WILL THEN MOVE OFFSHORE MONDAY NIGHT AS LOW PRESSURE APPROACHES FROM THE GREAT LAKES. THIS LOW WILL MOVE SLOWLY ACROSS THE AREA DURING THE MIDDLE OF THE WEEK BEFORE MOVING AWAY THURSDAY AND FRIDAY. MORE HIGH PRESSURE WILL BUILD IN FOR NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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LATEST ESTF UPDATE WE ARE GOING TO START WIND GUSTS A LITTLE FASTER AS MIXING IS GETTING TO A FAST START THIS MORNING. TEMPERATURES WERE ADJUSTED UP SLIGHTLY. SPRINKLES ARE REACHING THE GROUND IN HAZELTON, SO WE WILL KEEP A LOW CHANCE OF SPRINKLES/FLURRIES EARLY FAR NORTH. THE KATABATIC FLOW IS STARTING TO ERODE THE STRATOCU, SO NO BIG CHANGES TO SKY COVERAGE. THE WRF-NMMB INITIALIZATION LOOKED BETTER AT 500MB WHILE A COMPROMISE OF BOTH THE WRF AND GFS WORKED BEST AT 850MB AND 925MB. IF ANYONE WONDERED WHERE OCTOBER WENT, ITS BACK TODAY. IT WILL FEATURE A BLUSTERY FALL FEEL TO IT. ONE SHORT WAVE DOWN AND ONE TO GO THIS MORNING AS THE LONG WAVE TROF CLEARS OUR CWA. CLOUDINESS ASSOCIATED WITH THE LAST SHORT WAVE IS NOW MOVING ACROSS OUR CWA AND SHOULD CLEAR THE COAST BY ABOUT 13Z. THERE IS STILL THE MATTER OF THE NW FLOW OFF OF LAKE ONTARIO. MESOSCALE MODELS SUGGEST SOME LAKE ENHANCED PCPN MIGHT JUST MAKE IT INTO OUR POCONO CWA BEFORE DISSIPATING. WE CARRY A CHANCE OF SPRINKLES/FLURRIES EARLY THERE. AS THE MORNING PROGRESSES, THE FCST SUBSIDENCE INVERSION LOWERS AND THE CONVECTIVE TEMPS BECOME HARDER TO REACH. THERE SHOULD BE A PERIOD OF MOSTLY CLOUDY CONDITIONS THIS MORNING NORTH UNTIL THIS COMES TO FRUITION. LESS CLOUDINESS EXPECTED ELSEWHERE, ESPECIALLY IN THE SOUTHWEST PART OF OUR CWA. TEMPS HAVE FOUND A WAY TO OUTDO GUIDANCE AND WHILE LOCAL PROCEDURES SUGGEST GOING LOWER, WE KEPT CONTINUITY. IT WILL BE BREEZY/BLUSTERY TODAY, ESPECIALLY DURING THE MID DAY HOURS WHEN MIXING SHOULD BE MAXIMIZED. PEAK GUSTS BETWEEN 20 AND 30 MPH ARE LIKELY. IF THIS WERE HALLOWEEN, THE GREAT PUMPKIN WOULD HAVE NO PROBLEM GETTING AIRBORNE.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... FREEZE WARNING AND FROST ADVISORIES HAVE BEEN ISSUED FOR MOST OF OUR CWA NORTH OF DELMARVA EXCLUDING THE IMMEDIATE PHILADELPHIA AREA. BASED ON A COMPROMISE OF THE 925MB AND 850MB INITIALIZATION, WE USED A STRAIGHT STAT GUIDANCE BLEND FOR MINS. WHERE THIS GAVE US PREDOMINATE MINS OF FREEZING OR LESS IN THE COUNTIES, WE WENT WITH FREEZE WARNINGS. THE NJ PINE BARRENS FIND A WAY TO RADIATE LIKE THE BEST OF THEM. HERE WE WENT BELOW STAT GUIDANCE FOR THE FREEZE WARNING. THE FROST ADVISORY MAINLY SURROUNDS THESE COLDER SPOTS AND MOST LIKELY TO COME TO FRUITION IN THE MORE RURAL LOW LYING AREAS OF THOSE COUNTIES INCLUDED. IN DELMARVA, DEW POINTS ARE PREDICTED TO BE ABOVE CRITICAL LEVELS AND CONFIDENCE TO INCLUDE IS TOO LOW AT THIS TIME. WE WILL CONTINUE MENTION OF PATCHY FROST IN THE AFD. WINDS SHOULD DECOUPLE QUICKLY TONIGHT AND TEMPS DROP LIKE A ROCK DURING THE EVENING. OVERNIGHT A JET STREAK IS PREDICTED TO PASS ACROSS THE NORTHERN PART OF OUR CWA WITH CIRRUS LEVEL MOISTURE INCREASING. THERE IS RIDGING PREDICTED ALOFT AND NO PREDICTED OMEGA AT THE SUB CIRRUS LEVEL. THE COMBINATION LED TO OUR DECISION NORTH THAT THE CIRRUS MAY NOT BE THICK ENOUGH TO HOLD TEMPS ABOVE FREEZING. AS WE MOVE FARTHER SOUTH, THE ENTRANCE REGION TO THAT JET STREAK ARRIVES LATER AT NIGHT WITH LESS MOISTURE AND LESS TIME TO PREVENT FROST/FREEZING TEMPS FROM OCCURRING. THIS IS ALSO WHY DELMARVA WILL BE LOOKED CLOSELY TODAY AS THEY SHOULD HAVE LITTLE CIRRUS OVERNIGHT. FAR FAR NORTH MIGHT BE SAVED BY THE CIRRUS (CONFIDENCE TOO LOW ABOUT THAT TO NOT ISSUE A WARNING). BETWEEN THERE SHOULD BE A SWEET SPOT WHERE DEW POINTS ARE LOW ENOUGH AND THE CIRRUS ARRIVES TOO LATE. MESOSCALE MODELS SUGGEST THE LEHIGH AND RARITAN VALLEYS. THIS IS RATHER LATE FOR A FREEZE OR A WIDESPREAD FROST (THERE WAS SOME FROST INTO THE PHL NW SUBURBS EARLIER THIS MONTH) TO AFFECT OUR CWA. THE PLUS SIDE IS THAT IF PROTECTIVE MEASURES SUCCEED TONIGHT, FREEZING OR FROSTY CONDITIONS ARE NOT ON TAP FOR A WHILE. WE BROUGHT IN OUR MEYER LEMON TREE INDOORS YESTERDAY ANYWAY. && .LONG TERM /MONDAY THROUGH SATURDAY/... MONDAY...HIGH PRESSURE WILL BE CRESTING OVER THE AREA DURING THE MORNING BEFORE MOVING EAST. DRY WEATHER IS EXPECTED...ALTHOUGH CLOUDS WILL BE INCREASING OVER THE AREA DURING THE DAY. HIGH TEMPERATURES WILL REMAIN A BIT BELOW NORMAL WITH HIGHS IN THE LOW/MID 50S NORTH AND MID 50S OT LOW 60S ELSEWHERE. MON NIGHT THRU TUE NIGHT...LOW PRESSURE AT THE SFC AND A DEEPENING H5 LOW WILL BE WEST OF THE AREA. THIS WILL BE THE BEGINNING OF A RATHER EXTENDED PERIOD OF UNSETTLED CONDITIONS ACROSS OUR AREA. THIS FIRST FEW DAYS WILL BE SHOWERS WITH TEMPERATURES A BIT ABOVE NORMAL. SLGT CHC POPS MON NIGHT WILL INCREASE TO HIGH CHC/LOW LIKELY POPS BY TUE NIGHT. HIGHS TUE WILL TOP OUT IN THE LOW/MID 60S NORTH AND MID/UPPER 60S SOUTH. WED THRU THU NIGHT...UNSETTLED CONDITIONS CONTINUE WITH THE H5 LOW/TROUGH CROSSING THE AREA WED AND THE SFC LOW JUST AHEAD OF IT. FREQUENT PERIODS OF CLOUDS AND SHOWERS ARE EXPECTED THROUGH THE PERIOD. WE HAVE KEPT THE POPS OFFERED BY WPC WHICH ARE MOSTLY HIGH CHC CATEGORY WED THRU THU...THEN SLGT CHC THU NIGHT. TEMPERATURES WILL MOSTLY BE BELOW NORMAL WITH HIGHS MOSTLY IN THE 50S. FRI THRU SAT...HIGH PRESSURE WILL AFFECT THE WEATHER INTO NEXT WEEKEND. DRY WEATHER IS EXPECTED AT THIS TIME ALONG WITH MILDER TEMPERATURES. HIGHS ACROSS THE DEL VALLEY AND POINTS SOUTH/EAST WILL REACH THE LOW 60S FRI/SAT WHILE READINGS ACROSS THE NORTH/WEST WILL BE IN THE MID 50S TO AROUND 60. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/...
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12Z TAFS WILL FEATURE NO BIG CHANGES. WE BUMPED UP WIND GUSTS SLIGHTLY AND WILL BE ADDING A SOUTHWEST WIND CHANGE GROUP FOR KPHL FOR MONDAY MORNING. TIL 12Z...MAINLY A MID DECK VFR CIG FCST WITH WEST WINDS CLOSE TO 10 KTS WITH SOME GUSTS ADDED. HIGHER TERRAIN AIRPORTS WILL SEE SOME MVFR CIGS. NOT SURE ABOUT KABE REMAINING VFR. SUNDAY DAY...VFR CIGS POSSIBLE AT AIRPORTS MAINLY TO THE NORTH OF PHILADELPHIA AND INTERSTATE 195 IN NJ. EVEN SOME MVFR CIGS EARLY IN THE HIGHER TERRAIN. ELSEWHERE MAINLY JUST A SCATTERED DECK OF CU CLOUDS AFTER 12Z OR 13Z. NORTHWEST WINDS WILL AVERAGE AROUND 15 KNOTS WITH GUSTINESS AROUND 25 KNOTS. STAT GUIDANCE IS SUGGESTING THE PEAK WINDS SHOULD OCCUR BY ABOUT 18Z. CLEARING OR CLEAR SKIES AND DIMINISHING WINDS TOWARD SUNSET. SUNDAY NIGHT...VFR WITH LIGHTER NORTHWEST TO WEST WINDS BECOMING LIGHT AND VARIABLE AT MOST TERMINALS. ANY CLOUDS WILL BE AT CIRRUS LEVEL AND MORE LIKELY LATER AT NIGHT. OUTLOOK... MON AND MON NIGHT...MOSTLY VFR. INCREASING CLOUDS AND PERHAPS A FEW SHOWERS MON NIGHT. TUE THRU THU...UNSETTLED WITH CLOUDS AND FREQUENT SHOWERS. MOSTLY VFR BUT OCNL LOWER CONDITIONS EXPECTED IN SHOWERS.
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&& .MARINE... STRONG SMALL CRAFT ADVISORY CONDITIONS PREDICTED FOR TODAY. NW WINDS SHOULD PEAK AROUND 30 KNOTS. TONIGHT WE EXTENDED THE SMALL CRAFT ADVISORY FOR A COUPLE MORE HOURS IN DELAWARE BAY AND LEFT THE SAME ENDING TIME ON THE OCEAN. IN ALL LOCATIONS, THE GRADIENT WILL WEAKEN DURING THE EVENING AND OVERNIGHT AND SEAS AND SWELLS ON THE OCEAN SHOULD FALL BELOW 5 FEET BY MORNING. OUTLOOK... MON THRU TUE NIGHT...SUB VFR CONDITIONS. SHOWERS POSSIBLE TUE/TUE NIGHT. WED THRU FRIDAY...SCA CONDITIONS DEVELOPING WED AND LASTING INTO FRI. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FREEZE WARNING FROM 3 AM TO 8 AM EDT MONDAY FOR PAZ054-055-061- 062. FROST ADVISORY FROM 2 AM TO 8 AM EDT MONDAY FOR PAZ060-101>106. NJ...FREEZE WARNING FROM 3 AM TO 8 AM EDT MONDAY FOR NJZ001-007>010. FREEZE WARNING FROM 4 AM TO 8 AM EDT MONDAY FOR NJZ020>022-027. FROST ADVISORY FROM 2 AM TO 8 AM EDT MONDAY FOR NJZ012-013- 015>019-023. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ430- 431. && $$ SYNOPSIS...O`HARA NEAR TERM...GIGI SHORT TERM...GIGI LONG TERM...O`HARA AVIATION...GIGI/O`HARA MARINE...GIGI/O`HARA

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