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Area Forecast Discussion
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000
FXUS61 KPHI 182129
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
429 PM EST THU DEC 18 2014

.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 COLD
FRONT MAY MOVE THROUGH THE EASTERN SEABOARD ON CHRISTMAS EVE.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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. HIGH TEMPS U30S/L40S - NEAR NRML FOR MID DEC.

1026 SFC HIGH HAS MOVED INTO MI. CUTOFF LOW WL BE MOVG OVR NOVA
SCOTIA TNGT. XPCTG ST LYR TO DIMINISH AFTR SUNDOWN AND WNWRLY
WINDS TO WEAKEN AS WELL. LOWS TNGT RANGING FM THE M20S IN THE
POCONOS TO THE L30S NEAR WILDWOOD.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FRIDAY SHOULD BE DOMINATED BY GREAT LAKES HIGH PRESSURE WHICH
SHOULD YIELD PARTY CLOUDY SKIES.


&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
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 NIGHT - SATURDAY...LOOKS DRY. FRIDAY SHOULD BE DOMINATED BY
GREAT LAKES HIGH PRESSURE WHICH SHOULD YIELD PARTY CLOUDY SKIES.

SATURDAY NIGHT AND 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. ONLY HAVE SLIGHT CHANCE POPS ACROSS THE 
NORTHEASTERN PORTION OF THE CWA AS THAT LOOKS LIKE THE MOST 
FAVORABLE LOCATION FOR THE TONGUE TO MOISTURE TO REACH. GIVEN THE 
OVERNIGHT TIMING PRECIP COULD FALL AS RAIN SNOW MIX OR ALL SNOW. 

MONDAY - TUESDAY...LOW PRESSURE MOVES OFF THE CAROLINA COAST AND OUT 
TO SEA ON TUESDAY. THIS LOW WILL HELP LIFT A WARM FRONT ASSOCIATED 
WITH A LARGE AND DEVELOPING LOW PRESSURE SYSTEM OVER THE MIDDLE OF 
THE CONUS INTO THE AREA. ONSHORE FLOW AHEAD OF THE SYSTEM AND WARM 
AIR MOVING IN WITH THE FRONT WILL ALLOW FOR A WARMING LOW-LEVEL 
THERMAL PROFILE SO PRECIP SHOULD BE PRIMARILY LIQUID. MID-RANGE 
CHANCE POPS WILL PERSIST MONDAY...MONDAY NIGHT...AND TUESDAY. 

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. 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. IT APPEARS THAT CHRISTMAS
EVE WL BE A DAY W/ MOISTURE, WINDS, AND POSSIBLY CONVECTION. LKLY
POPS ARE IN THE FCST.

THURSDAY...CHRISTMAS DAY - DEEP LAYER ZONAL FLOW WILL FILL IN
ACROSS THE AREA. DRY CONDITIONS XPCTD AS THE COLD FRONT SHOULD BE
E OF THE AREA. A DEEP STACKED LOW WILL BE OVER THE EASTERN GREAT
LAKES. RIGHT NOW "COOL AND BRZY" COULD BE THE WX WORDS FOR THE DAY.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
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 WL BEGIN TO 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...
THE SMALL CRAFT ADVISORY NORTHERN WATERS WILL BE EXTENDED DEEPER
INTO THIS EVENING AS MORE FREQUENT GUSTS TO 25 KTS ARE POSSIBLE,
THE REST OF THE SMALL CRAFT ADVISORY WILL BE DROPPED.

GUSTS NEAR OR ABOVE 20 KT WILL BE POSSIBLE THROUGH THE OVERNIGHT
HOURS ELSEWHERE.

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.

&&

.EQUIPMENT...
ELECTRONIC TECHNICIANS BLV THEY HV FIXED A PROBLEM W/
THE KDIX 88D AND IT SHOULD RETURN TO SVC TDA.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ450-
     451.

&&

$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...
MARINE...GIGI/99
EQUIPMENT...






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