Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 171914
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
314 PM EDT WED SEP 17 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL RETREAT TONIGHT, BEFORE A WEAK FRONTAL
BOUNDARY MOVES ACROSS THE AREA THURSDAY. HIGH PRESSURE WILL RETURN
TO THE NORTHEAST THURSDAY NIGHT INTO FRIDAY, BEFORE PUSHING OFFSHORE
FRIDAY NIGHT. A WARM FRONT WILL LIFT TO OUR NORTHWEST SATURDAY, THEN
A COLD FRONT IS EXPECTED TO AFFECT THE AREA LATE SUNDAY INTO EARLY
MONDAY. THIS FRONT WILL SLOWLY MOVE TO OUR SOUTH, WHILE HIGH
PRESSURE BEGINS TO BUILD IN FROM THE WEST ON TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A LIGHT SOUTHERLY FLOW WILL CONTINUE OVERNIGHT AS HIGH PRESSURE
CONTINUES TO SLIDE OFF THE EAST COAST. WITH A SLIGHT INCREASE IN
MOISTURE, MAINLY CLEAR SKIES, AND NIGHTS THAT ARE GETTING LONGER,
PATCHY FOG IS ONCE AGAIN POSSIBLE LATE NIGHT. THE FOGGER TOOL WAS
USED TO INTRODUCE PATCHY FOG INTO THE WEATHER GRIDS. LOW
TEMPERATURES ARE EXPECTED TO RANGE IN THE LOW TO MID 40S IN THE FAR
NORTH, AND IN THE LOW TO MID 50S SOUTH, WHICH IS SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
A CHANGE IN WIND DIRECTION WILL OCCUR DURING THE DAY AS THE AXIS OF
A BROAD UPPER LEVEL TROUGH MOVES THROUGH THE NORTHEASTERN PORTION OF
THE COUNTRY. A SPRINKLE OR TWO CANNOT BE RULED OUT DURING THE
AFTERNOON HOURS SOUTH AND EAST OF THE I-95 CORRIDOR AS THIS AXIS
MOVES EAST, BUT RIGHT NOW PRECIPITATION IS NOT MENTIONED GIVEN THE
LOW CHANCES OF THIS ACTUALLY HAPPENING. LATER SHIFTS CAN RAISE THE
POPS SLIGHTLY IF SPRINKLES BECOME MORE LIKELY. HIGHS SHOULD REACH
THE MID 60S IN THE FAR NORTH, AND IN THE MID TO UPPER 70S
SOUTH...JUST ABOUT NORMAL FOR THIS TIME OF YEAR.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A MOSTLY DRY FORECAST TO START OUT, WITH A BETTER CHANCE OF RAIN
LATER IN THE WEEKEND.

HIGH PRESSURE IS EXPECTED TO BUILD BACK OVER THE AREA THURSDAY NIGHT
INTO FRIDAY, THEN PUSH OFFSHORE OF NEW ENGLAND FRIDAY NIGHT. WITH PW
VALUES LESS THAN ONE HALF/THREE QUARTERS OF AN INCH, WE EXPECT A
DRY FORECAST.

WITH THE HIGH OFFSHORE SATURDAY/SATURDAY NIGHT, RETURN FLOW DEVELOPS
WHICH WILL ALLOW DEWPOINTS TO BEGIN TO INCREASE ACROSS THE AREA. A
WARM FRONT WILL LIKELY LIFT TO OUR NORTHWEST, BUT MAY NOT PASS
CLOSE ENOUGH TO OUR AREA TO BRING ANY EFFECTS. THERE IS A WEAK
SHORT WAVE/VORTICITY IMPULSE SATURDAY, BUT WITH LIMITED VERTICAL
MOISTURE, WE DO NOT EXPECT ANY PRECIPITATION.

ON SUNDAY, A FRONTAL BOUNDARY WILL BE APPROACHING FROM THE WEST. WE
DO NOT EXPECT THE FRONT TO MOVE INTO OUR AREA UNTIL LATER ON SUNDAY,
BEFORE MOVING ACROSS THE AREA SUNDAY NIGHT INTO EARLY MONDAY. BOTH
THE GFS AND ECMWF DISSIPATE SOME OF THE PRECIPITATION BEFORE IT
REACHES OUR AREA, BUT THEY BOTH STILL HAVE SOME LIGHT QPF ACROSS
THE AREA. THEREFORE WE WILL KEEP A CHANCE OF SHOWERS SUNDAY NIGHT
INTO EARLY MONDAY. LITTLE IF ANY INSTABILITY IS FORECAST, SO WE DO
NOT HAVE THUNDERSTORMS IN THE FORECAST.

THE FRONT WILL SLOWLY PULL AWAY FROM THE AREA MONDAY NIGHT INTO
TUESDAY, WHILE HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. PW
VALUES DROP TO LESS THAN HALF AN INCH BY TUESDAY AND WEDNESDAY, SO
WE EXPECT DRY WEATHER AT THIS TIME.

TEMPERATURES THROUGH THE EXTENDED ARE ON A BIT OF A ROLLER
COASTER. SLIGHTLY BELOW FRIDAY, THEN ABOVE SATURDAY AND ESPECIALLY
SUNDAY, THEN NEAR NORMAL MONDAY, AND BACK BELOW TUESDAY AND
WEDNESDAY. NO EXTREMES ONE WAY OR THE OTHER THOUGH.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS

MOSTLY VFR CONDITIONS EXPECTED OVERNIGHT WITH A SOUTHERLY FLOW
GENERALLY LESS THAN 5 KNOTS. PATCHY FOG IS POSSIBLE...ESPECIALLY AT
KMIV AND KRDG, AS LOW LEVEL MOISTURE IS ADVECTED INTO THE REGION.

THE LIGHT SOUTHERLY FLOW WILL VEER TO THE NORTHWEST DURING THE DAY
AS THE AXIS OF AN UPPER LEVEL TROUGH MOVES EAST. WIND SPEEDS ARE
EXPECTED TO REMAIN BELOW 10 KT. A FEW SPRINKLES CANNOT BE RULED OUT
AT THE SOUTHERN TAF SITES AS THE TROUGH MOVES EAST, BUT ANY SUCH
ACTIVITY SHOULD HAVE LITTLE IMPACT ON AVIATION OPERATIONS.

OUTLOOK...
THURSDAY NIGHT-FRIDAY...MOSTLY VFR, EXCEPT POSSIBLY SOME FOG
OVERNIGHT THURSDAY/FRIDAY MORNING.

FRIDAY NIGHT...LOWER CIGS AND/OR VSBYS POSSIBLE WITH STRATUS/FOG
DEVELOPMENT OVERNIGHT WITHIN A PERSISTENT EASTERLY FLOW.

SATURDAY-SATURDAY NIGHT...MOSTLY VFR DURING THE DAY. LOWER CIGS AND/OR
VSBYS POSSIBLE WITH STRATUS/FOG DEVELOPMENT OVERNIGHT
SATURDAY/SUNDAY MORNING.

SUNDAY-SUNDAY NIGHT...LOWER CONDITIONS POSSIBLE EARLY, THEN VFR
DURING THE DAY. A COLD FRONT APPROACHES SUNDAY NIGHT WITH RAIN AND
LOWER CONDITIONS POSSIBLE.

MONDAY...SHOWERS POSSIBLE EARLY, THEN VFR. GUSTY W-NW WINDS
15-20 KNOTS.

&&

.MARINE...
SEAS IN THE 4 TO 5 FOOT RANGE WITH LONG PERIOD SWELLS ASSOCIATED
WITH EDOUARD ARE EXPECTED ON THE COASTAL WATERS TONIGHT INTO EARLY
THURSDAY. THEN SEAS START TO SUBSIDE AS EDOUARD MOVES EAST WELL AWAY
FROM THE EAST COAST. A LIGHT SOUTHERLY FLOW WILL SHIFT TO A LIGHT
NORTHWESTERLY FLOW LATER ON THURSDAY AS THE AXIS OF AN UPPER LEVEL
TROUGH MOVES EAST.

OUTLOOK...
THURSDAY NIGHT-FRIDAY NIGHT...WINDS MAY INCREASE CLOSE TO SMALL CRAFT
ADVISORY LEVELS BEHIND A WEAK FRONTAL BOUNDARY AS HIGH PRESSURE
BEGINS TO BUILD IN. SEAS MAY ALSO BEGIN TO BUILD FRIDAY INTO FRIDAY
NIGHT AS AN EASTERLY FETCH BUILDS ACROSS THE WATERS.

SATURDAY-SUNDAY...CONDITIONS EXPECTED TO DROP BELOW ADVISORY LEVELS,
BUT WINDS MAY GUST NEAR 20 KNOTS.

SUNDAY NIGHT...A COLD FRONT APPROACHES SUNDAY NIGHT WITH RAIN AND
INCREASING WINDS. WINDS MAY APPROACH SMALL CRAFT ADVISORY LEVELS
BEHIND THE COLD FRONT.

MONDAY...WINDS EXPECTED TO DROP BELOW ADVISORY LEVELS.

&&

.RIP CURRENTS...
A MODERATE RISK OF RIP CURRENTS CONTINUES TODAY AND THIS EVENING
PRIMARILY DUE TO THE LONG PERIOD SWELLS FROM EDOUARD, WHICH REMAINS
WELL OUT TO SEA. THE ENHANCED RIP CURRENT RISK COULD CONTINUE INTO
THURSDAY.

&&

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

&&

$$
SYNOPSIS...ROBERTSON
NEAR TERM...MIKETTA
SHORT TERM...MIKETTA
LONG TERM...ROBERTSON
AVIATION...ROBERTSON/MIKETTA
MARINE...ROBERTSON/MIKETTA
RIP CURRENTS...MIKETTA




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