Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 181511
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1011 AM EST THU DEC 18 2014

ISSUED BY NWS STERLING...

.SYNOPSIS...

LOW PRESSURE OVER ATLANTIC CANADA WILL TRACK TO THE NORTHEAST.
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES WILL MOVE INTO THE OHIO
VALLEY OVERNIGHT. LOW PRESSURE IS EXPECTED TO FORM OVER THE GULF
STATES FRIDAY NIGHT AND TRACK ACROSS GEORGIA SATURDAY. A BETTER
DEFINED LOW WILL FORM ALONG THE CAROLINA COAST AND MOVE NORTHEAST
OFF THE NEW JERSEY COAST MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...

UPDATE...

CURRENT FCST LOOKS IN GOOD SHAPE. CYCLONIC FLOW BTWN THE DEPARTING
LOW OVR P.E.I. AND HIGH OVER LAKE SUPERIOR IS CAUSING ABUNDANT LO LVL
MOISTURE TO BE BROUGHT INTO THE NERN U.S. AND W/ THIS CLD CVR
ACROSS ERN PA/NJ-AWAY FM THE SHORE. PRES GRAD IN PLACE IS CAUSING
WINDS TO GUST INTO THE M20S. TEMPS NEAR NRML FOR MID DEC.

WINDS DCRS TNGT. LOWS TNGT RANGING FM THE M20S IN THE POCONOS TO
THE L30S NEAR WILDWOOD.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
ONE LAST SHORT WAVE TROUGH ON THE BACK SIDE OF THE DEPARTING UPPER
LEVEL LOW WILL APPROACH THE REGION OVER NIGHT, BUT WITH CONTINUED
DRY AIR ADVECTION IN THE BOUNDARY LAYER, DO NOT EXPECT ANY
PRECIPITATION, ONLY INCREASING MID AND UPPER LEVEL CLOUDS ACROSS THE
NORTHERN HALF OF THE REGION. WITH THE SURFACE HIGH SLIDING CLOSER TO
THE REGION, EXPECT BOUNDARY LAYER WINDS TO DECOUPLE SOON AFTER
SUNSET. THIS COULD SET UP PRIME RADIATIONAL COOLING CONDITIONS OVER
THE SOUTHERN HALF OF THE REGION IF PREVIOUSLY MENTIONED MID AND
UPPER LEVEL CLOUDS STAY CONFINED TO THE NORTH. FOR NOW HOWEVER, HAVE
GENERALLY STAYED CLOSE TO THE GUIDANCE WHICH IS NEAR NORMALS.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MID-LEVEL FLOW THE NEXT COUPLE OF DAYS IS RATHER FLAT THOUGH A
CHANGE TO THAT PATTERN APPEARS LIKELY BY THE END OF THE WEEKEND. A
DEEP TROUGH EMERGES ACROSS THE CENTRAL U.S. BY TUESDAY AS MULTIPLE
PACIFIC NORTHWEST WAVES ROUND THE BASE OF THE TROUGH AND ACROSS OUR
REGION...WE ARE HEADING FOR A VERY UNSETTLED PERIOD BY EARLY NEXT
WEEK.

FRIDAY - SATURDAY...BOTH DAYS LOOK DRY. FRIDAY SHOULD BE DOMINATED
BY GREAT LAKES HIGH PRESSURE WHICH SHOULD YIELD PARTY CLOUDY SKIES.
THE PAST COUPLE OF DAYS SATURDAY LOOKED TO BE THE TRANSITION DAY
INTO THE STORMIER PATTERN BUT WITH THE ONCE EAST COAST STORM BEGAN
TO TREND WEAKER AND WEAKER WE LOOK TO BE DRIER AND DRIER. THERE IS
SOME NORTHERN STREAM ENERGY TO CONTEND WITH LATE SATURDAY NIGHT THAT
COULD TOUCH OFF A FEW SHOWERS AS IT PASSES THROUGH BUT THESE SHOULD
BE OF LITTLE CONSEQUENCE.

SUNDAY...AN INVERTED TROUGH MAY THROW BACK SOME MOISTURE ACROSS THE
AREA AS A WEAK WAVE OF LOW PRESSURE MOVES WELL OFFSHORE OF OUR
REGION. WHERE WE ONCE HAD LIKELY POPS HAVE NOW TRENDED TO CHANCE OR
SLIGHT CHANCE AND THERE IS THE POSSIBILITY OF NO CHANCE IN THE
COMING DAYS. AS FOR PTYPES, THE INTERIOR ZONES HAVE THE BEST CHANCES
OF SEEING SNOW ON SUNDAY MORNING BEFORE A SLIGHT WARMING TREND IS
EXPECTED. PRECIPITATION LOOKS TO BE LIGHT IN NATURE EVERYWHERE.

MONDAY - TUESDAY...ONCE THE AFOREMENTIONED SYSTEM ABOVE DEPARTS
ANOTHER, BETTER DEFINED SYSTEM MOVES OFF THE CAROLINA COAST AND OUT
TO SEA ON TUESDAY. ONSHORE FLOW AHEAD OF THE SYSTEM WILL ALLOW FOR A
WARMING LOW-LEVEL THERMAL PROFILE SO ANY PRECIPITATION WILL BE
LIQUID WITH SOME MIXING POSSIBLE IN THE FAR NORTHWESTERN ZONES.

WEDNESDAY...STILL WATCHING A LARGE LOW PRESSURE FORM TO OUR WEST AND
TRACK INTO THE GREAT LAKES REGION ON WEDNESDAY. THIS WOULD KEEP OUR
REGION UNDER A WARMING THERMAL PROFILE WITH A LOT OF MOISTURE TO
WORK WITH...AN ALL LIQUID EVENT IS EXPECTED AT THIS POINT. WHAT IS
INTERESTING WITH THE LATEST MODEL RUNS IS HOW THEY ARE SEEMINGLY
WEAKENING THE PRIMARY LOW AS IT MOVES INTO THE LAKES ALLOWING FOR
ANOTHER, STRONGER, PIECE OF PAC NW ENERGY TO PRODUCE CYCLOGENESIS
ACROSS THE MID-ATLANTIC. IF THIS EASTWARD TREND AND CYCLOGENESIS
CONTINUES WE COULD BE SINGING A DIFFERENT TUNE OVER THE NEXT SEVERAL
DAYS. NONE-THE-LESS, LOTS OF MOISTURE, WINDS, AND POSSIBLY
CONVECTION, ARE LOOKING BETTER AND BETTER...WE CONTINUE THE LIKELY
POPS THIS FAR IN ADVANCE.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TODAY..."LOW VFR" AT SITES AWAY FM THE SHORE: BKN-OVC 3500-4500 FT.
NW WIND GUSTS 22-30 KT SUBSIDE ARND SUNDOWN.

TONIGHT...VFR WITH SC SLOWLY DIMINISHING THOUGH SC MAY HOLD ON MUCH
OF THE NIGHT NEAR AND JUST N OF KABE/KRDG DUE TO A DEVELOPING INVERSION
NEAR 5000 FT. THERE WILL BE A PERIOD OF MID AND HIGH CLOUDS RACING
EWD BASICALLY NEAR AND SOUTH OF KLNS-KMJX NEAR 06Z/19. GUSTY NW
WINDS SUBSIDE SOMEWHAT...FEW GUSTS 15-20 KT.

OUTLOOK...
FRIDAY - SATURDAY...VFR. NORTHWEST WINDS VEER TOWARDS THE
NORTH-NORTHEAST BY SATURDAY.

SUNDAY - MONDAY...SUB-VFR POSSIBLE WITH SCATTERED RAIN/SNOW SHOWERS.

&&

.MARINE...
A SMALL CRAFT ADVISORY CONTINUES OVER THE BAY THROUGH NOON, AND
OVER THE ATLANTIC COASTAL WATERS THROUGH LATE THIS AFTERNOON.
NORTHWESTERLY WINDS OF 15 TO 25 KT, WITH OCCASIONAL GUSTS TO 30 KT
CAN BE EXPECTED. WINDS SHOULD BEGIN TO DIMINISH LATE THIS AFTERNOON.
HOWEVER, GUSTS NEAR OR ABOVE 20 KT WILL BE POSSIBLE THROUGH THE
OVERNIGHT HOURS.

OUTLOOK...
FRIDAY...MOSTLY SUB-ADVISORY CONDITIONS ARE EXPECTED. SOME NORTHWEST
WIND GUSTS COULD STILL BE IN THE 20 PLUS KNOT RANGE, THOUGH.
CONFIDENCE: ABOVE AVERAGE.

SATURDAY - SUNDAY...SUB-SCA EXPECTED FOR THE MOST PART. SEAS REMAIN
AROUND 3 TO 4 FEET.  CONFIDENCE: AVERAGE TO SLIGHTLY BELOW AVERAGE.

MONDAY...SCA CONDITIONS SHOULD PRESENT THEMSELVES LATER ON MONDAY
UNDER A STRENGTHENING EASTERLY FLOW AND BUILDING SEAS. CONFIDENCE:
AVERAGE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
     ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ430-431.

&&

$$
UPDATE...WOODY!
PRVS...DRAG/JOHNSON/HEAVENER






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