Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 252014
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
314 PM EST THU DEC 25 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE SOUTHEAST U.S. WILL BUILD EAST...REACHING
THE CAROLINA COAST FRIDAY EVENING BEFORE MOVING OFFSHORE ON
SATURDAY. A COLD FRONT IS FORECAST TO MOVE THROUGH OUR AREA SUNDAY
BEFORE SLOWING ITS SOUTHWARD PROGRESSION AS A WAVE OF LOW PRESSURE
MOVES ALONG IT ON MONDAY AND MONDAY NIGHT. HIGH PRESSURE WILL THEN
BUILD EAST TOWARD THE MID ATLANTIC STATES TUESDAY THROUGH
THURSDAY.
&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
STRATOCUMULUS DECK THAT MOVED IN AFTER THE BRIEF SUNSHINE BREAK IS
ALREADY STARTING TO SHOW SIGNS OF DISSIPATING, AND SHOULD CONTINUE
TO DO SO THROUGH EARLY THIS EVENING. WINDS WILL ALSO BE DIMINISHING
BY EARLY THIS EVENING. THIS, COMBINED WITH DEW POINTS IN THE 20S AND
30S SHOULD SET THE STAGE FOR PRIME RADIATIONAL COOLING CONDITIONS
OVERNIGHT. THEREFORE, UNDERCUT GUIDANCE ON LOWS FOR TONIGHT. MOST
PLACES, WITH THE EXCEPTION OF THE URBAN CORRIDOR FROM WILMINGTON TO
PHILLY AND CENTRAL DELMARVA, SHOULD DROP WELL BELOW FREEZING INTO
THE 20S OVERNIGHT.
&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
TOMORROW IS LOOKING PROMISING THAT WE WILL ACTUALLY SEE MOSTLY SUNNY
CONDITIONS FOR A GOOD PORTION OF THE DAY. DRY AIR ADVECTION WILL
CONTINUE IN NEARLY ALL LEVELS, AND AS MENTIONED BY THE PREVIOUS
SHIFT, CONVECTIVE TEMPS SHOULD NOT BE MET.

TEMPERATURE WISE, THERE IS STILL CONSIDERABLE DISAGREEMENT BETWEEN
THE MAV AND MET. GIVEN THE TRACK OF THIS HIGH BUILDING NE FROM THE
DEEP SOUTH AND GIVEN MODEST THICKNESS INCREASES, STAYED CLOSER TO
THE MAV.
&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A MID-LEVEL TROUGH OVER THE CENTRAL
ROCKIES AND A MID-LEVEL RIDGE OVER THE SOUTHEAST U.S. COAST. THIS
RIDGE MAINTAINS A SW FLOW OVER THE REGION THROUGH SUNDAY. THIS FLOW
THEN GRADUALLY BECOMES WESTERLY MON, THEN NORTHWESTERLY LATE WED OR
EARLY THU AS A MID-LEVEL LOW OVER HUDSON BAY PUSHES SOUTH.  IN TERMS
OF TEMPERATURES, THIS PATTERN SHOULD PROVIDE THE REGION WITH ABOVE
NORMAL TEMPERATURES THROUGH SUN, NEAR NORMAL TEMPERATURES ON MON AND
TUE, THEN BELOW NORMAL TEMPERATURES FOR THE REMINDER OF THE LONG TERM
PERIOD.

MEANWHILE...AT THE SURFACE, HIGH PRESSURE CENTERED OVER THE VA/NC
COAST FRI NIGHT WILL DRIFT OFFSHORE ON SAT ALLOWING A COLD FRONT TO
APPROACH FROM THE WEST ON SUNDAY. PRECIPITATION IN THE FORM OF RAIN
OR RAIN SHOWERS WILL OVERSPREAD THE AREA EARLY SUNDAY, CONTINUING
INTO THE EVENING HOURS. AS THE FRONT SAGS JUST TO OUR SOUTH, LOW
PRESSURE MAY FORM ALONG IT, CONTINUING THE PRECIPITATION THREAT
OVER THE SOUTHERN PORTIONS OF THE CWA INTO TUE. COLDER AIR ON THE
BACK OF THIS SYSTEM COULD CHANGE SOME OF THE LINGERING
PRECIPITATION TO SNOW BEFORE ENDING. THEN MORE HIGH PRESSURE BUILDS
IN FROM THE TENNESSEE RIVER VALLEY ON THU.
&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. STRATOCUMULUS
4000 TO 6000 FT AGL WILL SLOWLY DISSIPATE AFTER SUNSET. AT THAT
TIME, EXPECTING FEW IF ANY CLOUDS FOR THE REMAINDER OF THE TAF
PERIOD. WINDS SHOULD DIMINISH BY EARLY THIS EVENING (WITH THE
POSSIBLE EXCEPTION OF COASTAL LOCATIONS INCLUDING KACY) AND REMAIN
WESTERLY OR SOUTHWESTERLY WITH SPEEDS GENERALLY NEAR OR BELOW 10KT.

OUTLOOK...
FRIDAY NIGHT AND SATURDAY...VFR.

SATURDAY NIGHT...SOME MVFR CIGS POSSIBLE NORTHWEST AIRPORTS, VFR CIGS
ELSEWHERE.

SUNDAY INTO MONDAY...MVFR, POSSIBLY IFR, CONDITIONS POSSIBLE AT
TIMES AS WAVES OF PRECIPITATION MOVE FROM NORTH TO SOUTH ACROSS THE
AREA. THE NORTHERN PART OF THE PRECIPITATION SHIELD COULD BE SNOW.

MONDAY NIGHT AND TUESDAY...VFR.
&&

.MARINE...
WINDS WILL SLOWLY DIMINISH THROUGH THE EVENING HOURS. ALL WATERS
SHOULD BE BELOW SCA CRITERIA BY LATE THIS EVENING. FOR LATE TONIGHT
AND TOMORROW, WINDS WILL STAY OUT OF THE WEST NORTHWEST WITH GUSTS
NEAR 20KT.

OUTLOOK...
FRIDAY THROUGH MONDAY...SUB SMALL CRAFT ADVISORY CONDITIONS
EXPECTED. A WEAK COLD FRONTAL PASSAGE IS EXPECTED SUNDAY.

LOWEST CONFIDENCE IS ON MONDAY AS A WAVE OF LOW PRESSURE IS
PREDICTED TO FORM SOUTH OF THE AREA WATERS ON THE MENTIONED FRONT.
ITS POSSIBLE THAT SMALL CRAFT ADVISORY CONDITIONS MIGHT OCCUR IF
THIS LOW INTENSIFIES FASTER THAN WE ARE CURRENTLY FORECASTING.
&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ431-
     450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430.

&&

$$
SYNOPSIS...MIKETTA
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...MIKETTA
AVIATION...JOHNSON/MIKETTA
MARINE...JOHNSON/MIKETTA





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