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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPHI 240153
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
953 PM EDT THU MAY 23 2013

.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE REGION TONIGHT INTO FRIDAY. A
LOW PRESSURE SYSTEM WILL DEVELOP ON THE FRONT OFF THE NEW JERSEY
COAST FRIDAY AND SLOWLY MOVE NORTHEAST REACHING THE CANADIAN
MARITIMES ON MONDAY. HIGH PRESSURE WILL THEN BUILD EAST IN ITS
WAKE EARLY NEXT WEEK. A WARM FRONT IS FORECAST TO MOVE THROUGH THE
FORECAST AREA ON TUESDAY INTO WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
THUNDERSTORMS WERE INTO EASTERN PA, NORTHWEST NJ AND THE MD
EASTERN SHORE LATE THIS EVENING. THEY WERE RUNNING AHEAD OF THE
COLD FRONT THAT WAS EXPECTED TO ENTER OUR FAR WESTERN ZONES BY
MIDNIGHT. SURFACE BASED CAPES WERE SHOWING STABLE AIR ADVANCING
FROM THE ATLANTIC TO MEET THE ACTIVITY SOMEWHERE AROUND THE
DELAWARE VALLEY. THE MAIN CHANGE (OTHER THAN TO MAKE A NOWCAST IN
THE VERY NEAR TERM GRIDS) WAS TO BACK OFF A BIT ON THE
STRENGTH/POSSIBILITY OF THUNDER AS ONE MOVES INTO THE EASTERN PART
OF THE FORECAST AREA AND THE ATLANTIC. FOR THE WESTERN AND PERHAPS
THE CENTRAL PART OF THE FORECAST AREA, THE THUNDER, HEAVY RAIN
AND GUSTY WINDS STILL LOOK ON TARGET. TEMPERATURES WERE MAINLY
LEFT ALONE, EXCEPT WE HAD TO NUDGE DOWN THE HOURLIES FOR A COUPLE
OF HOURS ALONG THE COAST THANKS TO THE INTRUSION OF STABLE AIR.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
EARLY FRIDAY, A SURFACE COLD FRONT IS PROGGED TO BE JUST EAST OF OUR
FORECAST AREA, CONTINUING TO SLOWLY PROGRESS OFFSHORE THROUGH THE
DAY. MEANWHILE, A MID LEVEL LOW WILL BE DROPPING SOUTH ACROSS THE
REGION THROUGH THE COURSE OF THE DAY, AND WE HAVE KEPT CHANCE TO
LIKELY POPS FOR SHOWERS IN PLACE ACROSS THE FORECAST AREA. GUSTY
NORTHWEST WINDS ARE EXPECTED TO DEVELOP ACROSS THE REGION THROUGH
THE DAY, WITH GUSTS REACHING AROUND 25 MPH. COOLER AND DRIER AIR
WILL BE FILTERING IN ACROSS THE MID ATLANTIC, AND MAXIMUM
TEMPERATURES WILL BE NOTICEABLY COOLER THAN IN RECENT DAYS, WITH
HIGHS MAINLY FROM THE LOWER 60S FOR OUR NORTHWEST AREAS TO THE
MIDDLE AND UPPER 60S IN SOUTHERN NJ AND THE DELMARVA.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
LOW PRESSURE WILL MOVE SLOWLY NORTHEASTWARD AND AWAY FROM THE AREA
FRIDAY NIGHT INTO SATURDAY AS AN UPPER LEVEL TROF IS SLOW TO EXIT.
UNFORTUNATELY, THIS MEANS THAT SATURDAY, WHICH LOOKED LIKE A NICE
WX DAY EARLIER IN THE WEEK DOESN`T LOOK NEARLY AS NICE ATTM. THERE
WILL BE SHOWERS OVERNIGHT INTO SAT MRNG. THEN, CONDS WILL SLOWLY
IMPROVE AS THE DAY PROGRESSES. HOWEVER, THERE WILL STILL BE AN
ABUNDANCE OF CLOUDS AND DECENT NWLY FLOW UNTIL THE LOW CLEARS THE
AREA. THE BEST CHC OF PRECIP LOOKS TO BE OVER NERN AREAS.

HIGH PRESSURE WILL BUILD DOWN BEHIND THE DEPARTING LOW AND THIS
WILL KEEP A DECENT NWLY FLOW SAT NIGHT INTO SUN. HOWEVER, OVERALL
CONDS WILL CONTINUE TO IMPROVE AND CERTAINLY BY SUN THERE WILL BE
MORE SUNSHINE WHICH WILL CONTINUE INTO MON.

THE HIGH WILL MOVE EWD AND OFF THE CST BY TUE AS A WMFNT
APPROACHES AND THEN PASSES THRU THE REGION AND THEN A STRONG RIDGE
ALOFT BEGINS TO DEVELOP OVER THE AREA. POPS WILL BE INTRODUCED TO
THE FCST AROUND TUE INTO WED WITH THE WMFNT.

TEMPS WILL BE MUCH BELOW NRML SAT, IN SOME CASES 10 TO 15
DEGREES BELOW NRML....THEN TEMPS REBOUND A BIT ON SUN AND MON
BEFORE RISING TO ABV NRML VALUES BY WED.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

WE FORECAST THUNDER FOR THE NORTHWESTERN SITES WITH SOME GUSTY
WINDS (AROUND 30 KNOTS) LATE THIS EVENING. WE FORECAST THUNDER
THROUGH AROUND MIDNIGHT BUT DO NOT PLAY UP THE WINDS OVER THE
DELAWARE VALLEY SITES. WE HAVE KEPT THE THUNDER OUT OF THE
SOUTHEASTERN SITES BECAUSE OF THE STABLE AIR AND LOW CLOUDS THAT
HAVE MOVED IN. IF ANY THUNDER OCCURS THERE, IT SHOULD BE ELEVATED.
DURING THE OVERNIGHT HOURS, WE EXPECT CEILINGS TO LOWER TO IFR
ACROSS MUCH OF THE AREA. WINDS WILL CONTINUE TO BE MAINLY OUT OF
THE SOUTH UNTIL THE COLD FRONT MOVES ACROSS THE AREA, AND THEN
THERE SHOULD BE A RELATIVELY PLACID SHIFT IN THE WINDS TO WEST.

FRIDAY...IFR CONDITIONS WILL LIKELY BEGIN THE DAY, WITH IMPROVEMENT
TO MVFR EXPECTED BY MID-MORNING. WINDS WILL BECOME NORTHWESTERLY
AND THEN BECOME RATHER GUSTY BY MID-MORNING, WITH GUSTS IN THE 20
TO 30 KNOT RANGE EXPECTED THEN THROUGH THE AFTERNOON TO EARLY
EVENING.


OUTLOOK...
FRI NIGHT THROUGH SAT...MVFR TO POSSIBLY IFR CONDITIONS DUE TO
CLOUDS AND SHOWERS. WORST CONDITIONS EXPECTED AT NORTHEASTERN
TERMINALS AND AIRPORTS. CONDITIONS COULD IMPROVE AS SATURDAY
CONTINUES. NORTH TO NORTHWEST WIND GUSTS COULD EXCEED 20 KTS. LOW
CONFIDENCE ON TIMING OF IMPROVING CONDS.

SAT NIGHT THRU MON...MOSTLY VFR. SOME GUSTY NORTHWEST WINDS
POSSIBLE ON SUNDAY. HIGH CONFIDENCE.

TUE...MAINLY VFR. LWR CIGS/VSBYS PSBL LATER IN THE DAY WITH WARM
FRONT AND RAIN.  MDT CONFIDENCE.
-- End Changed Discussion --

&&

.MARINE...
WITH AN APPROACHING COLD FRONT NEARING THE REGION THIS EVENING AND
TONIGHT, WE MAINTAIN A SMALL CRAFT ADVISORY FOR OUR COASTAL WATERS,
WITH WIND GUSTS IN THE 20 TO 25 KNOT RANGE AND SEAS AROUND 5 FEET.
FOLLOWING THE COLD FRONT PASSAGE DURING FRIDAY MORNING, WINDS WILL
TURN AND BECOME NORTHWESTERLY FOR OUR WATERS THROUGH FRIDAY. WIND
GUSTS WILL PICK UP INTO THE 25 TO 30 KNOT RANGE, WITH SEAS AROUND 5
TO 6 FEET FOR OUR COASTAL WATERS. IN ADDITION, WE HAVE RAISED A
SMALL CRAFT ADVISORY FOR DELAWARE BAY STARTING 18Z FRIDAY, AS WIND
GUSTS AND SEAS ARE EXPECTED TO REACH CRITERIA DURING FRIDAY
AFTERNOON.

OUTLOOK...
THE SCA FLAG HAS BEEN EXTENDED INTO SAT MRNG AND MAY
NEED TO BE EXTENDED FURTHER. ALSO, HAVE EXPANDED SCA TO INCLUDE
DEL BAY. WITH THE LOW OFF THE COAST AND STRONG HIGH PRESSURE
BUILDING IN, THERE WILL BE STRENGTHENING NWLY FLOW THRU SAT SEAS
WILL REMAIN ELEVATED AND THE WIND WILL HIT SCA AS WELL. SOME GUID
IS EVEN INDICATING GALE POTENTIAL ON SAT, BUT CONFIDENCE IS LOW
ENOUGH ON THAT ATTM THAT NO HEADLINES WERE ISSUED. AFTER ABOUT
SUNDAY MORNING. AFTER NO ADDITIONAL MARINE FLAGS ARE ANTICIPATED
THRU THE PD.

&&

.RIP CURRENTS...
-- Changed Discussion --
WE FORECAST A MODERATE RISK OF DANGEROUS RIP CURRENTS ALONG THE
COAST OF NEW JERSEY AND DELAWARE ON FRIDAY.
-- End Changed Discussion --

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY FROM 2 PM FRIDAY TO 8 AM EDT SATURDAY FOR
     ANZ430-431.

&&

$$
SYNOPSIS...NIERENBERG
NEAR TERM...KLINE/DELISI
SHORT TERM...KLINE
LONG TERM...NIERENBERG
AVIATION...KLINE/NIERENBERG/DELISI
MARINE...KLINE/NIERENBERG
RIP CURRENTS...DELISI