-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 102319
AFDCTP

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

.SYNOPSIS...
SNOW WILL MOVE QUICKLY TO THE EAST THIS MORNING. A VERY COLD AND
BRISK WEST TO NORTHWEST FLOW WILL DEVELOP IN THE WAKE OF THIS
SYSTEM...AND BRING MUCH COLDER AIR WITH BELOW NORMAL TEMPERATURES
GRIPPING THE REGION THROUGH MID TO LATE WEEK. MODERATE TO LOCALLY
HEAVY LAKE EFFECT SNOWS ARE ALSO FORECAST IN PERENNIAL SNOWBELT
ACROSS THE NORTHWEST MOUNTAINS INTO THE SECOND HALF OF THE WEEK.
ELSEWHERE...IT WILL BE GENERALLY COLD AND DRY. THE ACTIVE EARLY
SEASON WINTER PATTERN LOOKS TO RESUME WITH ANOTHER STORM SYSTEM
LIKELY AFFECTING THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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ASIDE FROM LAKE CLOUDS FLIRTING WITH THE NORTHERN TIER AND
NORTHWEST MOUNTAINS FOR MOST OF THE NIGHT...THE REMAINDER OF
CENTRAL PA WILL BE MOSTLY CLEAR AND MUCH COLDER TONIGHT.
THE FLOW ACROSS LAKE ERIE IS TOO WRLY TO MAKE MUCH MORE THAN A
FLURRY OVER THE FAR NW - EVEN OVER WARREN CO THIS EVENING - AS
THIS SHOULD KEEP ANY LAKE EFFECT BANDS TO THE NORTH FOR A LITTLE
WHILE. FLOW IS FAVORABLE FOR WARREN CO TO GET A MINOR ACCUM
OVERNIGHT...MAINLY EARLY. THEN...THE MEAN 1000-850 FLOW BECOMES
VEERS TO 260 DEGREES...SO THAT MIGHT KEEP ANY SNOW AT OR EVEN TO
THE NORTH OF THE NY BORDER. 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.
-- End Changed Discussion --

&&

.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 /23Z TUESDAY 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 SHOWERS IN THE
VICINITY. WINDS WILL BE GUSTY THRU THE NIGHT...THOUGH. GUSTS INTO
THE 20S ARE POSSIBLE IN THE WEST. 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...DANGELO/LA CORTE