Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 242023 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 423 PM EDT SUN APR 24 2016 .SYNOPSIS...
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HIGH PRESSURE WILL REMAIN OVER THE EASTERN SEABOARD THROUGH TONIGHT BEFORE SHIFTING OFFSHORE ON MONDAY. A FRONTAL BOUNDARY IS FORECAST TO STALL NEAR THE PENNSYLVANIA-NEW YORK BORDER MONDAY THROUGH TUESDAY MORNING. THE FRONT WILL EVENTUALLY PROGRESS SOUTHWARD THROUGH THE AREA TUESDAY AFTERNOON AND NIGHT. THE COLD FRONT WILL MOVE SOUTH OF OUR AREA WEDNESDAY AS HIGH PRESSURE NOSES DOWN FROM THE NORTHWEST. THE FRONT MAY RETURN BACK NORTHWARD TOWARD THE REGION THURSDAY AND FRIDAY AS AN AREA OF LOW PRESSURE TRACKS ALONG IT. HIGH PRESSURE TRIES TO BUILD IN FROM THE NORTHWEST EARLY NEXT WEEKEND BEFORE ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE GREAT PLAINS.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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WINDS WILL BECOME LIGHT AND VARIABLE EARLY...THEN GRADUALLY BECOME SOUTHWEST IN THE 5 TO 10 MPH RANGE AS SURFACE HIGH PRESSURE BUILDS OFFSHORE. SKIES ARE EXPECTED TO REMAIN MOSTLY CLEAR THROUGH THE OVERNIGHT HOURS EXCEPT FOR SOME HIGH CLOUDS IN THE FAR NORTH. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 30S IN THE FAR NORTH TO THE MID 40S IN THE SOUTH...JUST A TAD BELOW NORMAL FOR THIS TIME OF YEAR. SMOKE FROM A WILD FIRE IN MONROE COUNTY PENNSYLVANIA IS BEING ADVECTED INTO NORTHWESTER NEW JERSEY LATE THIS AFTERNOON, AND RESIDENTS IN THAT AREA MAY EXPERIENCE HAZY SKIES AND THE SMELL OF SMOKE INTO THE EVENING HOURS.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
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THE SOUTHWESTERLY FLOW WILL BECOME MORE ESTABLISHED AS THE DAY WEARS ON. THERE COULD BE SOME GUSTS IN THE 15 TO 20 MPH RANGE... ESPECIALLY IN THE AFTERNOON. MOSTLY CLEAR SKIES IN THE MORNING WILL GIVE WAY TO INCREASING CLOUDS DURING THE AFTERNOON. A LIGHT RAIN SHOWER OR SPRINKLE CANNOT BE RULED OUT IN THE FAR NORTH WITH AN APPROACHING FRONT, AND SLIGHT CHC POPS HAVE BEEN ADDED TO THE GRIDS ACCORDINGLY. RELATIVE HUMIDITIES WILL ALSO BE ON THE INCREASE, WITH DEWPOINT TEMPERATURES RISING INTO THE UPPER 40S BY THE END OF THE DAY, COMPARED TO MID 20S SUNDAY AFTERNOON. HIGHS ON MONDAY WILL GENERALLY RANGE FROM THE LOW TO MID 70S, SEVERAL DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
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&& .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
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A LARGE LOW PRESSURE SYSTEM IS FORECAST TO CUTOFF OVER EASTERN CANADA THROUGH MUCH OF THE UPCOMING WEEK AND POSSIBLY INTO NEXT WEEKEND. THE LONG TERM IS LOOKING RATHER ACTIVE WITH THE MID- ATLANTIC REGION SITUATED ON THE SOUTHWESTERN PERIPHERY OF THE SYSTEM`S BROAD CYCLONIC FLOW WHILE A WEST-EAST ORIENTED FRONT WAVERS NEARBY. THE POSITION OF THIS BOUNDARY WILL BE A KEY PLAYER IN DETERMINING HOW UNSETTLED THE PERIOD TURNS OUT BUT THE ODDS OF OUR AREA RECEIVING APPRECIABLE RAINFALL ARE HIGHER THAN IN RECENT WEEKS. A SOUTHWARD SHIFT IN THE DEVELOPMENT OF A WEST-EAST FRONTAL BOUNDARY WAS NOTED WITH TODAY`S MODEL RUNS COMPARED TO YESTERDAY`S. THIS FRONT IS EXPECTED TO STALL NEAR OR JUST NORTH OF I-80 CLOSE TO THE NY-PA AND NY-NJ BORDER MONDAY NIGHT AND TUESDAY MORNING. THE BEST CHANCES FOR SHOWERS DURING THIS TIME LOOKS TO BE IN OUR FAR NRN ZONES THAT RESIDE CLOSE TO THE FRONT ALTHOUGH THE WIDESPREAD OVERRUNNING PRECIP NORTH OF THE BOUNDARY WILL LIKELY STAY TO OUR NORTH. AN AREA OF LOW PRESSURE THAT IS CURRENTLY OVER THE NORTHERN PLAINS IS FORECAST TO TRACK EASTWARD ALONG THE FRONT, PASSING JUST ACROSS OUR NE PA AND NW NJ EARLY TUESDAY MORNING. NW FLOW BEHIND THE LOW WILL FINALLY ALLOW THE BOUNDARY TO PUSH SOUTHWARD THROUGH THE AREA AS A COLD FRONT TUESDAY AFTERNOON AND EVENING. TEMPERATURES WILL BE HIGHLY DEPENDENT ON THE EXACT POSITION OF THIS FRONT AS WE EXPECT AN IMPRESSIVE N-S TEMPERATURE GRADIENT ACROSS THE AREA ON TUESDAY WITH TEMPS ONLY IN THE 60S NORTH OF THE FRONT AND 80S SOUTH. SHOWERS ARE LIKELY ACROSS THE AREA ON TUESDAY WITH THE BEST CHANCE FOR THUNDERSTORMS JUST SOUTH OF THE BOUNDARY. THERE IS A RISK FOR SEVERE THUNDERSTORMS ACROSS OUR SOUTHERN AREAS THAT IS CONDITIONAL ON SUNSHINE DURING THE PEAK HEATING HOURS THAT WOULD SUFFICIENTLY DESTABILIZE THE BOUNDARY LAYER IN THE PRE-FRONTAL WARM SECTOR. THE D3 OUTLOOK FROM SPC HAS INCLUDED PHILA AND ITS SOUTHERN SUBURBS IN A MARGINAL RISK FOR SEVERE STORMS. THE FRONT WILL EVENTUALLY MOVE SOUTH OF THE AREA LATE TUESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM CENTRAL CANADA. WEDNESDAY WILL FEATURE DRY CONDITIONS AND NEAR NORMAL TEMPS WITH HIGH PRESSURE RIDGING INTO OUR AREA. THE FRONTAL BOUNDARY TO OUR SOUTH IS THEN EXPECTED TO RETURN BACK NORTHWARD THURSDAY AND FRIDAY AS ANOTHER WAVE OF LOW PRESSURE ORGANIZES OVER THE FRONT RANGE AND TRACKS EASTWARD ALONG THE BOUNDARY. IT IS STILL UNCERTAIN HOW FAR NORTH THE FRONT MAKES IT BUT MODEL CONSENSUS POINTS TO IT MAKE IT CLOSE ENOUGH THAT OVERRUNNING PRECIP EXPANDS NORTHWARD INTO THE DELMARVA AND PERHAPS SE PA/S NJ BY THURSDAY AND FARTHER NORTHWARD BY FRIDAY. HIGH PRESSURE TRIES TO BUILD BACK INTO THE REGION BY SATURDAY BUT THE FRONT MAY RETURN BACK NORTHWARD LATER IN THE WEEKEND AS YET ANOTHER WAVE OF LOW PRESSURE APPROACHES FROM THE WEST.
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&& .AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS EXPECTED TONIGHT AND MONDAY. NORTHWESTERLY WINDS IN THE 5 TO 10 KT RANGE ARE EXPECTED THROUGH LATE AFTERNOON...BEFORE BECOMING LIGHT AND VARIABLE THIS EVENING...THEN VEERING TO THE SOUTHWEST DURING THE LATE OVERNIGHT HOURS AS HIGH PRESSURE SLIDES OFF THE MID-ATLANTIC COAST. THE ONLY EXCEPTION WILL BE AT ACY WHERE A SOUTHEAST SEA BREEZE WIND HAS SET UP SHOP FOR THIS AFTERNOON. WIND SPEEDS COULD REACH INTO THE 10 TO 15 KNOT RANGE ON MONDAY AS THE PRESSURE GRADIENT INCREASES WITH AN APPROACHING FRONT. SKIES SHOULD REMAIN MOSTLY CLEAR DURING THE OVERNIGHT HOURS, WITH SOME HIGH CLOUDS POSSIBLE MONDAY AFTERNOON...ESPECIALLY AT THE NORTHERN TAF SITES. OUTLOOK... MONDAY NIGHT THROUGH TUESDAY EVENING...SHRA ALONG A FRONT INITIALLY FAVORED OVER NRN TERMINALS THRU EARLY TUESDAY MORNING. MOST AREAS TO THE SOUTH OF THESE SHRA WILL REMAIN VFR. NUMEROUS SHRA AND SCT TSTMS EXPECTED TUESDAY AFTERNOON AND EVENING AS THE FRONT MOVES SWD. PERIODS OF MVFR WITH TEMPORARY IFR RESTRICTIONS POSSIBLE WITH THIS CONVECTIVE ACTIVITY. LATE TUESDAY NIGHT...IMPROVING TO VFR FROM N TO S. WEDNESDAY AND WEDNESDAY NIGHT...MAINLY VFR. THURSDAY AND FRIDAY...SHOWERS RETURN BACK INTO THE AREA. CEILING AND VISIBILITY VALUES MAY DROP INTO THE MVFR CATEGORY, ESPECIALLY ACROSS OUR SRN TERMINALS.
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&& .MARINE...
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SUB-ADVISORY CONDITIONS ARE EXPECTED TONIGHT AND MONDAY ACROSS ALL THE FORECAST WATERS. A LIGHT NORTHWESTERLY WIND WILL GRADUALLY VEER TO A SOUTHWESTERLY DIRECTION AS HIGH PRESSURE MOVES OFFSHORE. THIS SOUTHWESTERLY FLOW IS EXPECTED TO INCREASE INTO THE 10 TO 15 KNOT RANGE LATER MONDAY AS A FRONTAL BOUNDARY APPROACHES FROM THE NORTH. OUTLOOK... MONDAY NIGHT INTO TUESDAY...SWLY WINDS INCREASE TO AROUND 20 KT BUT WE MAY STRUGGLE TO SEE HIGHER GUSTS TO 25 KT IN OUR COASTAL WATERS. SEAS WILL BUILD TO AROUND 4 TO PERHAPS 5 FT. SCA MAY NEED TO BE ISSUED BUT HELD OFF ON A 3RD/4TH PERIOD HEADLINE DUE TO THE MARGINAL SETUP. TUESDAY NIGHT...SCA CONDITIONS POSSIBLE AS WINDS TURN NELY BEHIND A COLD FRONT AND MAY GUST TO 25 KT. WEDNESDAY THROUGH FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.
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&& .FIRE WEATHER...
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WINDS ARE EXPECTED TO DIMINISH THIS EVENING AND OVERNIGHT AS HIGH PRESSURE MOVES EAST...THEN OFF THE COAST MONDAY MORNING. SOUTHWESTERLY WINDS ARE EXPECTED TO PICK UP ON MONDAY AFTERNOON INTO THE 15 TO 20 MPH RANGE AS A FRONT APPROACHES FROM THE NORTH. HOWEVER...THIS SAME SOUTHWESTERLY FLOW WILL PUSH DEWPOINT TEMPERATURES INTO THE MID TO UPPER 40S, COMPARED TO MID 20S ON SUNDAY, WHICH IN TURN WILL RAISE RELATIVE HUMIDITY LEVELS INTO THE MID 40S AND LOW 50S MONDAY AFTERNOON. SO WHILE THE WINDS MAY BE SLIGHTLY STRONGER, RELATIVE HUMIDITIES WILL BE HIGHER TOO.
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&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLEIN NEAR TERM...MIKETTA SHORT TERM...MIKETTA LONG TERM...KLEIN AVIATION...KLEIN/MIKETTA MARINE...KLEIN/MIKETTA FIRE WEATHER...MIKETTA

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