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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 101727
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1227 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 /THROUGH TONIGHT/...
-- Changed Discussion --
SNOW ENDING QUICKLY AND RIGHT ON SCHEDULE. STRONG WESTERLY WINDS
WILL DOWNSLOPE IN THE SE AND CLEAR UP MUCH OF THE AREA THIS
AFTERNOON. LATEST VISIBLE IMAGES SHOW BIG BREAKS IN THE WESTERN
PART OF THE STATE BUT SOME UPSLOPE CLOUDS ARE EXPECTED OVER THE
WRN MTS FOR THE REST OF THE AFTN. OTHERWISE...THE FLOW ACROSS LAKE
ERIE IS TOO WRLY TO MAKE MUCH MORE THAN A FLURRY OVER THE FAR NW -
EVEN OVER WARREN CO - AS THIS SHOULD KEEP LAKE EFFECT BANDS TO THE
NORTH FOR A LITTLE WHILE. WINDS BRING HIGHER RH BACK INTO THE NW
BY SUNSET...SO THE CLOUDS SHOULD INCREASE AGAIN THERE. FLOW IS
FAVORABLE FOR WARREN CO TO GET A MINOR ACCUM OVERNIGHT...MAINLY
EARLY. THEN THE MEAN 1000-850 FLOW BECOMES MORE LIKE 260
DEGREES...SO THAT MIGHT KEEP ANY SNOW AT OR EVEN 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 WITH
MOS GUIDANCE TONIGHT...IN THE TEENS.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
IN THE WAKE OF THE FAST-MOVING WINTER SYSTEM...A VIGOROUS
CYCLONIC/NW FLOW PATTERN WILL GRIP THE REGION WITH BELOW NORMAL
TEMPS AND LAKE EFFECT SNOWS THROUGH THE END OF THE WEEK. A
REINFORCING SHOT OF COLD AIR FOLLOWING THE PASSAGE OF A NRN
CLIPPER ON WED WILL HELP SUPPORT PERSISTENT...MAINLY W-E ORIENTED
LES BANDS OVER THE PERENNIAL NW SNOWBELT IN NRN WARREN/MCKEAN COS
WITH ACCUMS IN EXCESS OF 6" POSSIBLE BY THE END OF THE PD.

OTHER THAN THE LES SNOW IN THE NW MTNS...MUCH OF THE REMAINDER OF
THE AREA WILL BE COLD AND DRY. A CONSENSUS OF ALL MAX TEMP
GUIDANCE SHOWS DAYTIME DEPARTURES OF -20F ACROSS MUCH OF THE AREA
THU. WIND CHILLS WILL BE VERY COLD ESPECIALLY AT NIGHT AND IN THE
EARLY MORNING WITH VALUES IN THE SINGLE DIGITS EITHER SIDE OF
ZERO. HIGHLIGHTED THE WIND CHILLS IN THE HWO.

THE GFS/ECMWF EVENTUALLY SHOW THE LAKE EFFECT WINDING DOWN AS
HIGH PRESSURE ARRIVES IN THE MID-ATLC ON FRIDAY.

THE ACTIVE EARLY SEASON WINTER PATTERN LOOKS TO RESUME BY THE
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-ATLC/NORTHEAST STATES. WHILE
THERE IS REASONABLE CONVERGENCE OF SOLUTIONS ON A STORM
SYSTEM...THE DETAILS WILL NEED SORTING-OUT AT SHORTER RANGES TO
DETERMINE SENSIBLE WX IMPACTS SUCH AS TIMING AND PTYPES. AT FIRST
GLANCE...THE SET-UP IS SOMEWHAT SIMILAR TO THIS PAST SUNDAY`S
SYSTEM WITH MIXED PRECIP AGAIN A CONCERN. THE COLD AIR PRECEDING
THE NEW SYSTEM SHOULD BE MORE ROBUST WHICH SUGGESTS AN INCREASED
CHANCE FOR FROZEN/FREEZING PTYPES.

INCREASED POPS AROUND DAY 5 WITH REASONABLE MODEL AGREEMENT
HOWEVER CONFIDENCE IN TIMING IS BELOW AVG GIVEN DIFFS IN THE
OPRN GFS/EC AND THEIR RESPECTIVE ENSEMBLE MEANS.
-- End Changed Discussion --

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
SNOW HAS ENDED FOR TODAY. WILL KEEP ANY MENTIONS OUT OF MOST OF
THE TAFS FOR 18-23Z. EXPECT CONDITIONS TO IMPROVE EXTREMELY
RAPIDLY...WITH CIGS RISING AND BREAKING OUT. VFR DOMINATING
CONDITIONS AFTER 19Z. THE ONLY CAVEAT WILL BE BFD WHERE THERE
SHOULD BE A DROP IN CIGS AND VSBYS TO MVFR/IFR LATER THIS EVENING
OR OVERNIGHT TONIGHT DUE TO WRLY FLOW AND LAKE EFFECT SHOWERS.

OUTLOOK...
WED...PM SHSN/REDUCED VSBYS POSSIBLE W MTNS.
THU...SHSN/REDUCED VSBYS POSSIBLE NW MTNS.
FRI...NO SIG WX EXPECTED.
SAT...MIXED PRECIP WITH LOW CIGS/VSBYS POSSIBLE.
-- End Changed Discussion --

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NONE.
-- End Changed Discussion --

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...DANGELO