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[Printable]
056
FXUS61 KCTP 201518
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1018 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SUBSIDENCE INVERSION MAINTAINING THE GLOOMY SKIES THIS MORNING...
WHILE DECAYING MID-UPPER CLOUD FROM UNDERCUTTING SHORTWAVE SOUTH
OF THE MASON DIXON LINE IS LIFTING ACROSS SOUTHWEST AND CENTRAL
AREAS. LITTLE IF ANY SUNSHINE WILL BE SEEN FOR YET ANOTHER
DAY. THIS AND LOW DECEMBER SUN ANGLE WILL RESULT IN HIGHS ONLY
IN THE LOW TO MID 30S MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...DEVOIR/RXR




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