Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 281419
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1019 AM EDT MON JUL 28 2014

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL CONTINUE TO LIFT INTO NEW ENGLAND
TODAY, PULLING A COLD FRONT ACROSS THE AREA. HIGH PRESSURE WILL
BEGIN MOVING INTO THE AREA LATER TUESDAY, AND REMAIN IN CONTROL OF
THE WEATHER FOR THROUGH THE END OF THE UPCOMING WEEK. A FRONTAL
BOUNDARY OVER THE OCEAN WILL DRIFT BACK CLOSE TO THE COAST OVER
THE WEEKEND.


&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS HAVE ENDED ACROSS THE AREA AS THE
INITIAL SHORT WAVE/VORT MAX HAS MOVED TO OUR NORTHEAST. A WEAK
SURFACE TROUGH IS MOVING ACROSS THE AREA NOW, AND ANOTHER MAY
DRIFT ACROSS THE AREA THROUGH THE DAY BEFORE THE MAIN COLD FRONT
PROGRESSES ACROSS THE AREA LATER TODAY INTO THIS EVENING. THE
MID-LEVEL TROUGH AND ASSOCIATED COLD POOL SPINNING TO OUR
NORTHWEST AS EVIDENT BY SATELLITE DATA WILL CONTINUE LIFTING
NORTHEASTWARD THROUGH THE DAY. IT WILL STILL BE NEARBY DURING THE
PEAK HEATING HOURS TO ALLOW FOR INSTABILITY SHOWERS, AND ISOLATED
CONVECTION...ALSO POSSIBLE ALONG THE FRONTAL BOUNDARY. SHOULD
REMAIN BELOW SEVERE LIMITS TODAY AS WE ARE NOT EXPECTING A
SIGNIFICANT AMOUNT OF INSTABILITY. WINDS WILL BECOME GUSTY LATER
THIS MORNING INTO THIS AFTERNOON WITH A COOLER AND DRIER AIRMASS
FILTERING IN. DAYTIME HIGHS ARE EXPECTED TO BE SEVERAL DEGREES
COOLER THAN YESTERDAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
PRESSURE GRADIENT WILL TAKE A WHILE TO RELAX LATER TONIGHT SO NOT
EXPECTING MUCH DECOUPLING TO OCCUR...A WEAK AND SHALLOW INVERSION
MAY FORM ACROSS THE OUTLYING AREAS. CONTINUED MIXING SHOULD BE
ENOUGH TO KEEP TEMPERATURES FROM FALLING OFF THE TABLE TONIGHT,
THOUGH WITH THE COOLER AIRMASS IN PLACE CAN GIVE THE AIR
CONDITIONERS A BREAK. BLEND OF THE MET/MAV WAS USED.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A MOSTLY DRY START TO THE LONG TERM FORECAST, WITH PRECIPITATION
CHANCES INCREASING LATER IN THE WEEK INTO THE WEEKEND.

MUCH OF THE UPCOMING WEEK IS EXPECTED TO REMAIN MOSTLY DRY AS PW
VALUES DROP TO AN INCH OR LOWER FOR TUESDAY AND WEDNESDAY, BUT MAY
RETURN TO 1-1.25 INCHES FOR THURSDAY AND NEAR 1.5 INCHES FOR
FRIDAY. HIGH PRESSURE AT THE SURFACE WILL BUILD ACROSS THE REGION,
WHILE THE BROAD MID/UPPER TROUGH REMAINS IN PLACE ACROSS MUCH OF
THE EASTERN HALF OF THE COUNTRY. THERE AREA NO SIGNIFICANT SHORT
WAVE/VORTICITY IMPULSES THAT ARE FORECAST TO MOVE THROUGH FOR MUCH
OF THE WEEK, BUT WITH THE TROUGH IN PLACE AND DAYTIME HEATING,
THERE COULD BE ENOUGH DAYTIME INSTABILITY TO CREATE ISOLATED
SHOWERS OR THUNDERSHOWERS FOR THE LATTER HALF OF THE WEEK. EACH
DAY THE CHANCES INCREASE SLIGHTLY AND EXPAND IN COVERAGE. HOWEVER,
WE DO NOT HAVE MORE THAN A SLIGHT CHANCE PROBABILITY THROUGH
FRIDAY AT THIS TIME.

AS WE MOVE INTO NEXT WEEKEND, WE GET A MORE SOLID RETURN OF MOISTURE
ACROSS THE AREA AS PW VALUES REBOUND O 1.25-1.5 INCHES. WE ALSO HAVE
A BETTER CHANCE OF VORTICITY IMPULSES AFFECTING OUR AREA WITHIN THE
SOUTHWEST FLOW ALOFT, AND WITH THE COASTAL FRONT TRYING TO PUSH BACK
CLOSER TO SHOWER, WE MAY HAVE A FOCUS FOR PRECIPITATION TO FORM.
THEREFORE THE PRECIPITATION CHANCES INCREASE INTO NEXT WEEKEND.

TEMPERATURES THROUGH THE EXTENDED ARE FORECAST TO BE CLOSE TO OR
SLIGHTLY BELOW NORMAL.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TODAY...MOSTLY VFR CONDITIONS OCCURRING THIS MORNING, WITH A FEW
AREAS OF MVFR CIGS OCCURRING NOW, MAINLY NORTHERN AREAS. ALL CIGS
SHOULD LIFT TO VFR BY MID-DAY AND WILL REMAIN SO THROUGH THE DAY.
GUSTY SOUTHWEST WINDS VEERING TOWARDS THE WEST THIS AFTERNOON.
SCATTERED TO ISOLATED SHOWERS AND A FEW RUMBLES OF THUNDER ARE
POSSIBLE...MOSTLY NORTH AND WEST OF PHL.

TONIGHT...VFR. SHOULD LOSE GUSTS BY LATE THIS EVENING BUT KEEP
HIGHER SUSTAINED THROUGH THE OVERNIGHT HOURS WITH TIGHTER PRESSURE
GRADIENT.

OUTLOOK...
TUESDAY-WEDNESDAY NIGHT...MAINLY VFR
THURSDAY-FRIDAY...MAINLY VFR. ISOLATED SHOWERS/THUNDERSTORMS
POSSIBLE BOTH AFTERNOONS, ESPECIALLY FRIDAY.

&&

.MARINE...
TODAY...WE CONTINUE THE SMALL CRAFT FOR ALL OUR WATERS TODAY, THOUGH
IT MAY BE A TAD TOUGHER TO REACH THE 5 FOOT SEAS ACROSS OUR SOUTHERN
WATERS THAN PREVIOUSLY THOUGHT. SURFACE COLD FRONT NEARS FROM THE
WEST LATER TODAY AND WINDS SHIFT TOWARDS THE WEST-NORTHWEST. GUSTS
ARE EXPECTED TO OCCUR AHEAD AND BEHIND THE FRONT...UPWARDS OF 25
KNOTS...BETTER CHANCE NORTH.

TONIGHT...EXTENDED THE SMALL CRAFT FOR OUR NORTHERN TWO ZONES
THROUGH TONIGHT WHERE THE TIGHTER PRESSURE GRADIENT EXISTS AND
BETTER VERTICAL TRANSPORT MAY STILL OCCUR. SEAS WILL TAKE A BIT
LONGER TO COME DOWN, EVEN ONCE THE WINDS VEER TOWARDS THE WEST.

OUTLOOK...
TUESDAY-FRIDAY...SMALL CRAFT ADVISORY CONDITIONS POSSIBLE EARLY
TUESDAY MORNING, SUBSIDING AND REMAINING BELOW ADVISORY LEVELS THROUGH
THE PERIOD.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ430-
     431-452>455.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ450-451.

&&

$$
SYNOPSIS...ROBERTSON
NEAR TERM...HEAVENER
SHORT TERM...HEAVENER
LONG TERM...ROBERTSON
AVIATION...HEAVENER/ROBERTSON
MARINE...HEAVENER/ROBERTSON





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