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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 110308
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1008 PM EST TUE DEC 10 2013

.SYNOPSIS...
-- Changed Discussion --
BELOW NORMAL TEMPERATURES WILL GRIP THE REGION THROUGH MID TO
LATE WEEK. SOME LAKE EFFECT SNOW WILL AFFECT FAR NORTHWEST
PORTIONS OF THE NORTHWEST MOUNTAINS. ELSEWHERE...IT WILL BE
GENERALLY DRY. THE ACTIVE EARLY SEASON WINTER PATTERN LOOKS TO
RESUME WITH ANOTHER STORM SYSTEM LIKELY AFFECTING THE AREA OVER
THE WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LAKE CLOUDS AFFECTING PORTIONS OF THE WEST CENTRAL MOUNTAINS AND
SOME MAY YIELD A FEW FLURRIES. THE EXTENSIVE LAKE CLOUDINESS WILL
REMAIN ACROSS THE NORTHERN TIER THANKS TO A DECIDEDLY WLY FETCH.
SOME LIGHT SNOW SHOWER ACTIVITY WILL AFFECT THE NORTHERN TIER AND
NORTHWEST MOUNTAINS...BUT THE REMAINDER OF CENTRAL PA WILL BE
MOSTLY CLEAR AND MUCH COLDER TONIGHT. FLOW IS FAVORABLE FOR
WARREN CO TO GET A MINOR ACCUM OVERNIGHT. THEN...THE MEAN 1000-850
FLOW BECOMES VEERS TO 260 DEGREES...SO THAT MIGHT PUSH ANY SNOW AT OR
EVEN TO THE NORTH OF THE NY BORDER BY MORNING. MINS AND WINDS WILL
COMBINE TO PRODUCE WIND CHILLS NEAR ZERO ACROSS THE ALLEGHENIES
AND LAURELS. WILL KEEP MINS RIGHT IN LINE WITH MOS GUIDANCE IN THE
TEENS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
TROUGH MOVING DOWN FROM THE NRN PLAINS WILL BACK THE WINDS A BIT
IN THE AFTERNOON OVER THE NWRN HALF OF THE AREA. WHILE THIS MIGHT
TAKE THE LAKE EFFECT TO THE NORTH...IT WILL ALSO BRING SOME
ADDITIONAL MOISTURE AND ENERGY. THUS...A RETURN OF CLOUDS AND SCT
SHSN IS ON ORDER FOR THE ALLEGHENIES AND LAURELS. TEMPS MAY ONLY
RISE 5-6F IN THE NORTH. THE DOWNSLOPE FLOW WILL HELP A LITTLE IN
THE SE...BUT SNOW PACK -8C 8H TEMPS AND SHORT DAYLIGHT WILL KEEP
IT FROM RISING MORE THAN 10-12F THERE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
TROUGH PERSISTS ALOFT OVER THE REGION WED NIGHT INTO FRI...WITH
REINFORCING SHOT OF COLDER AIR WED NIGHT INTO THU. AT THE
SURFACE...HIGH PRESSURE BUILDS OVER THE THE OHIO/MISSOURI
VALLEYS...KEEPING CENTRAL PA IN PERSISTENT NW FLOW. THIS WILL KEEP
MENTION OF SNOW SHOWERS IN THE NW MTNS /WITH GRADUAL ACCUMS IN
EXCESS OF 6 INCHES POSS/ THROUGH MUCH OF THE WEEK...AND BRINGS A
QUICK SHOT OF VERY COLD AIR INTO THE REGION FOR WED NIGHT INTO THU
NIGHT. HIGHS ON THU WILL LINGER IN THE TEENS ACROSS THE HIGHER
TERRAIN AND ONLY REACH THE MID 20S IN THE SE. THESE READINGS ARE A
SOLID 15-20F BELOW NORMAL...COMBINED WITH A BREEZY WEST WIND WILL
BRING WIND CHILL READINGS FROM 5F TO AS LOW AS -10F.

LAKE EFFECT EVENTUALLY WINDS DOWN AND TEMPS BEGIN TO MODERATE
/THOUGH STILL REMAIN BELOW NORMAL/ AS HIGH PRESSURE ARRIVES IN
THE MID-ATLANTIC ON FRIDAY. BUT THE ACTIVE EARLY SEASON PATTERN
WILL BRING THE POTENTIAL FOR MORE WINTRY WEATHER THIS WEEKEND...AS
THE ENERGETIC SPLIT FLOW UPSTREAM MERGES OVER THE CENTRAL
STATES... ALLOWING LOW PRESSURE TO DEVELOP IN THE LWR MS REGION
AND TRACK NEWD INTO THE MID-ATLANTIC/NORTHEAST STATES. WHILE
THERE IS REASONABLE CONVERGENCE OF SOLUTIONS ON A STORM
SYSTEM...AS USUAL WITH SYSTEMS SEVERAL DAYS OUT...THE DETAILS WILL
NEED SORTING-OUT AT SHORTER RANGES TO DETERMINE SENSIBLE WX
IMPACTS SUCH AS TIMING AND PTYPES. PRECIPITATION ARRIVES STARTING
SAT MORNING AS LIGHT SNOW...WITH CORE OF HEAVIEST PRECIP PROGGED
TO REMAIN TO OUR SE AS ENERGY TRANSFERS TO COASTAL LOW /MILLER-B/.
BUT INCREASING SE FLOW OFF OF THE ATLANTIC WILL SURGE WARMER AIR
INTO THE REGION...BUT CURRENT PROGS SHOW 850MB TEMPS REMAINING
BELOW 0C...KEEPING THIS PRIMARY A MIXED PRECIP EVENT. BIGGEST
IMPACTS ARE EXPECTED SAT NIGHT...WITH QPF VARIABLE BUT GENERALLY
AVERAGING AROUND 0.25 IN THE NW TO 0.50 IN THE SE...WITH ACCUMS
TAPERED BECAUSE OF MIXED PRECIP. 12Z GFS IS TRENDING COLDER THAN
PREV RUN...BRINGING IT MORE IN LINE WITH ECMWF. STORM STRENGTH AND
TRACK ARE COMPARABLE WITH THIS MODEL CYCLE. DID CONTINUE TREND OF
INCREASING POPS DURING THESE PERIODS.

SYSTEM MOVES AWAY SUNDAY INTO SUN NIGHT...WITH ANOTHER STRONG AND
COLD HIGH PRESSURE AREA MOVING IN BY MONDAY. TEMPS MODERATE
SOMEWHAT BY MIDWEEK AS FLOW VEERS TO THE W/SW AHEAD OF ANOTHER
WAVE DROPPING ACROSS THE GREAT LAKES FOR TUE/WED.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR WILL DOMINATE FOR ALL BUT BFD THROUGH WED. BFD WILL HAVE A
DROP IN CIGS AND VSBYS TO MVFR LATER THIS EVENING OR OVERNIGHT
TONIGHT DUE TO WNW WINDS AND SOME LAKE EFFECT SNOW SHOWERS IN THE
VICINITY. CLOUDS MAY ALSO RETURN TO JST LATER TONIGHT OR EARLY
WED AS UPSLOPE CONTINUES...BUT CONDITIONS SHOULD REMAIN MAINLY VFR
IN THE VERY DRY AIRMASS.

A TROUGH CAUGHT IN THE FAST WESTERLIES WILL THICKEN AND LOWER THE
CLOUDS WED AFTN AND EVENING...AND WILL LIKELY LEAD TO MORE SNOW
SHOWER ACTIVITY FROM JST-BFD...THE USUAL HIGH TERRAIN CULPRITS.
THE REST OF THE AREA WILL STAY VFR FOR MUCH OF THE TIME. HIGH
PRESSURE WILL BUILD OVER THE TN VALLEY AND SRN APPALACHIANS FOR
LATE WEEK.

OUTLOOK...

THU-FRI...NO SIG WX.

SAT-SUN...SNOW OR MIXED PRECIP WITH LOW CIGS/VSBYS POSSIBLE.

&&

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

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE