Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 222209
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
609 PM EDT MON SEP 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE MID-ATLANTIC REGION TONIGHT AND
TUESDAY, THEN INTENSIFY OVER NEW ENGLAND ON WEDNESDAY. BY THURSDAY,
LOW PRESSURE WILL DEVELOP TO OUR SOUTH BRINGING A CHANCE FOR RAIN
TO AREAS MAINLY SOUTH OF PHILADELPHIA. WEAKER BUT PERSISTENT HIGH
PRESSURE SHOULD MAINTAIN MOSTLY FAIR WEATHER FOR FRIDAY THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE OVER THE OHIO VALLEY LATE THIS AFTERNOON WILL BUILD
EASTWARD OVERNIGHT. THE DAYTIME CLOUDS WILL DECREASE ACROSS THE
AREA...LEAVING MOSTLY CLR SKIES AFTER SUNSET. WINDS WILL DECREASE
AS WELL...AND SHOULD SETTLE TO AROUND 5 KTS OVERNIGHT. LOWS WILL
BE COOL...WITH SOME LOW 40S NORTH/WEST AND MID/UPPER 40S IN MOST
OTHER AREAS. LOOKS TOO DRY FOR ANY WIDESPREAD FOG...A BIT OF
PATCHY FOG POSSIBLE HOWEVER.

HIGHS TODAY (CALENDAR DAY) WERE GENERALLY AROUND 3 DEGREES BELOW
NORMAL RANGING FROM NORMAL AT KACY TO 6 BELOW NORML AT KMPO.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
HIGH PRESSURE WILL SETTLE OVER THE AREA TUESDAY. ANOTHER FAIR
WEATHER DAY IS EXPECTED WITH PLEASANT TEMPERATURES AND A
COMFORTABLE AIR MASS. HIGHS WILL BE SIMILAR TO TODAY...WITH
READINGS IN THE 60S NORTH/WEST...RANGING TO THE LOW 70S OVER NJ
AND THE DELMARVA. WINDS WILL BE GENTLE...MOSTLY NRLY AT 5 TO 10
MPH.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE EXTENDED PERIOD STARTS OUT FAIRLY QUIET ON TUESDAY NIGHT AND
WEDNESDAY...BUT THEN THINGS GET SMWHT MORE INTERESTING STARTING
WEDNESDAY NIGHT AND CONTINUING THROUGH THURSDAY. AN UPPER LOW IS
FCST TO DEVELOP OVER THE CAROLINAS TONIGHT FROM THE SRN END OF
THE ERN U.S. TROUGH NOW MOVING THROUGH. THIS UPPER LOW WILL BE CUT
OFF FROM THE MAIN BAND OF WESTERLIES ACROSS NRN US AND SRN CAN AND
ITS PREDICTABILITY SEEMS TO BE BELOW AVERAGE. ALTHOUGH NOT A
STRONG FEATURE...THE MODELS DISAGREE ON ITS FUTURE BEHAVIOR AND
ALSO ASSOCIATED SFC FEATURES.

HIGH PRES NOW BUILDING FROM THE MIDWEST INTO THE MID-ATLANTIC
REGION IS FCST TO BE REINFORCED OVER NEW ENGLAND BY WEDNESDAY...
AND THEN LOW PRESSURE ASSOCD WITH THE UPPER SYS BEGINS TO DEVELOP
ALONG THE SERN SEABOARD...SMWHT EAST OR WEST DEPENDING ON THE
MODEL. EITHER WAY THE RESULT IS INCREASING PRES GRADIENT AND ON-
SHORE WINDS OVER THE MID ATLANTIC REGION. THERE MAY NOT BE MUCH
FORCING FOR UVV...OR THE MAX FORCING STAYS OFFSHORE...BUT CLOUDS
AND MOISTURE ARE EXPECTED TO SPREAD NWD THRU DELMARVA INTO NJ
STARTING WED OR WED NIGHT AND CONTINUING THROUGH THU.

HAVE INCREASED POPS SMWHT FOR THU ALTHOUGH STILL IN THE CHANCE
RANGED DUE TO UNCERTAINTY. MOST LIKELY AREA FOR PRECIP IS
GENERALLY S/E OF PHL. PRECIP AMOUNTS SHOULD REMAIN ON THE LIGHT
SIDE. THE MAIN THREATS WITH THIS SYSTEM WOULD LIKELY BE WINDS AND
WAVES ALONG THE NJ/DE COAST AND ALSO OVER THE MARINE AREAS.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TONIGHT...REMAINING PATCHES OF SC NEAR 5000 FT WILL CLEAR THIS
EVENING JUST LEAVING SCT CIRRUS AOA 25000 FT. NW WIND G 15-18 KT
NOW WILL BECOME LIGHT NORTHERLY DURING THE NIGHT.

WEDNESDAY...VFR SCT CLOUDS AOA 5000 FT WHICH MEANS SOME PATCHY
CIRRUS BUT ALSO SOME AFTERNOON SCT NEAR 5000 FT. LIGHT NORTH WIND
BECOMING S-SE OVER KPHL AREA SOUTH AND EASTWARD DURING THE
AFTERNOON.


OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...VFR CONDITIONS EXPECTED.

THURSDAY...CLOUDY SKIES BUT STILL MOSTLY VFR CONDITIONS EXPECTED.
THERE IS SOME CHANCE FOR MVFR CONDS TO DEVELOP...ESPECIALLY FOR
ACY/MIV AND AREAS S/E OF PHL. SMWHT GUSTY E TO NE WINDS ARE ALSO
POSSIBLE FROM VCNTY PHL AND SEWD.

FRIDAY AND SATURDAY...VFR CONDITIONS EXPECTED WITH GENERALLY LIGHT
WINDS.

&&

.MARINE...
SCA CANCELLED. WINDS GUSTS AND SEAS WILL PROBABLY BE BELOW THE
SCA CRITERIA THROUGH TUESDAY. FAIR WEATHER IS EXPECTED THROUGH
TUESDAY. WINDS WILL TURN NORTHERLY BY TUESDAY MORNING.

OUTLOOK...
WEDNESDAY AND THURSDAY...WINDS AND SEAS WILL LIKELY INCREASE TO
SCA CRITERIA ON WED AND CONTINUE THROUGH THURSDAY AND POSSIBLY INTO
FRIDAY. THERE IS ABOVE AVERAGE UNCERTAINTY ABOUT THIS SITUATION
BUT WINDS AND SEAS ARE LIKELY TO BE HIGHER FOR WATERS EAST OF
DELAWARE VS ERN NJ. NOTE THE WAVEWATCH MODEL IS FCSTG SEAS 8 TO 10
FT ON THURSDAY...BUT IT IS DRIVEN BY THE GFS WHICH HAS STRONGER
SFC WINDS COMPARED TO THE NAM AND ECMWF.

SATURDAY...WIND/WAVES SHOULD REMAIN BELOW SCA CRITERIA.

&&

.RIP CURRENTS...
HAVE JUST CANCELLED THE HIGH RISK FOR THE FORMATION OF DANGEROUS
RIP CURRENTS AND ALL PRODUCTS ARE UPDATED. SWELLS HAVE DECREASED
1.5 FEET SINCE MIDDAY AND THEREBY THE RISK AS WELL.

HOWEVER...LOOKING AHEAD POTENTIAL FAIRLY BIG SURF LOOMS FOR THURSDAY
(BIGGER THAN TODAYS) AS A NEAR GALE ONSHORE FLOW SHOULD DEVELOP
AND SEAS/SURF BUILD. A MODERATE OR HIGH RISK FOR THE FORMATION OF
DANGEROUS RIP CURRENTS WILL LIKELY REDEVELOP.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...AMC
NEAR TERM...DRAG/O`HARA 609
SHORT TERM...O`HARA
LONG TERM...AMC
AVIATION...AMC/DRAG/O`HARA 609
MARINE...AMC/DRAG/O`HARA 609
RIP CURRENTS...609






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