Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 101636
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1136 AM EST WED FEB 10 2016

.SYNOPSIS...
A DEEP UPPER TROUGH WILL ESTABLISH ITSELF OVER THE NORTHEASTERN
U.S. OVER THE NEXT SEVERAL DAYS. A CONSTANT NORTHWEST FLOW WILL
BRING IN THE COLDEST AIR OF THE SEASON AS WELL AS CREATE A
PROLONGED PERIOD OF SNOW SHOWERS IN THE SNOW BELT AND LAUREL
HIGHLANDS.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
MOSTLY CLOUDY SKIES AND BLUSTERY CONDITIONS WITH FLURRIES AND A
FEW BRIEF SNOW SHOWERS WILL BE FOUND ACROSS MUCH OF THE CENTRAL
RIDGE AND VALLEY REGION THIS AFTERNOON INTO THIS EVENING WITH WEAK
LLVL RIDGING IN PLACE.

PERSISTENT UPSLOPE SNOW SHOWERS AND FREQUENT LES FROM MEANDERING
BANDS ACROSS THE FAR NW ZONES WILL BRING AN ADDITIONAL 1 TO 2 INCHES
OF SNOW THIS AFTERNOON...THOUGH PORTIONS OF NW WARREN COUNTY COULD
SEE 3 TO 4 INCHES OF NEW POWDERY SNOW BY DUSK THANK TO A WELL
ALIGNED SFC-800 MB FLOW FROM ABOUT 270 DEGREES /THAT WILL VEER TO
ABOUT 295 DEG LATE TODAY AS A SECONDARY COLD FRONT SWINGS SE
THROUGH THE AREA/. THIS SFC FEATURE...AND RATHER COMPACT UPPER
VORTLOBE SHOULD SUPPORT A 1 TO 3 HOUR PERIOD OF MORE
FREQUENT/QUASI NE/SW BANDS OF SNOW SHOWERS BRIEF SQUALLS CAPABLE
OF BRINGING A QUICK 1/2 INCH ALONG AND EAST OF THE INTERSTATE
99/RT 22 CORRIDOR.

BASED ON THE MODERATELY STRONG...WELL ALIGNED...AND PERSISTENT 280-290
DEG FLOW LATE TODAY THROUGH ABOUT 04Z FRIDAY...WILL STRONGLY CONSIDER
EXTENDING THE CURRENT WINTER WX AND LES ADVISORIES AND WARNINGS
OUT IN TIME BY UP TO 12 HOURS...AND EXPAND THEM TO COVER ELK AND
CLEARFIELD COUNTIES - WITH THE ISSUANCE OF THE MID AFTERNOON
FORECAST/GRIDDED DATA UPDATE.

NUDGED HOURLY AND MAX TEMPS A BIT TWD THE LATEST CONSENSUS BLEND
WHICH RESULTED IN JUST SOME MINOR MODIFICATIONS TO FCST HIGHS
THIS AFTERNOON WHICH ARE AROUND 20F ACROSS THE LAUREL HIGHLANDS
AND IN THE U20S TO LOWER 30S HEADING FROM THE CENTRAL MTNS TO THE
MIDDLE AND LOWER SUSQ VALLEY.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM THURSDAY/...
SHORT WAVE TROUGH SWINGS THRU THIS EVENING AND CARVES THE BASE OF
THE BIGGER TROUGH. THIS MAY LEAD TO A BRIEF PERIOD OF BETTER
ORGANIZATION TO THE UPSLOPE SNOW AND PUSH SOME ACCUMULATION OVER
THE ALLEGHENY FRONT INTO THE CENTRAL/RIDGE AND VALLEY REGION.
BUT ACCUMS IN THAT AREA WOULD BE ONLY AN INCH OR SO. IT GETS
UNIFORMLY COLDER ALL UP/DOWN THE COLUMN TONIGHT AND THE SATURATED
DGZ IS PIERCED THRU BY THE BEST UPWARD FORCING/OMEGAS. THUS...IT
SHOULD BE PRETTY EASY TO GET A FLUFFY SNOW OUT OF THE ATMOS
TONIGHT. SLR/S COULD BE 25:1 OR 30:1. SO EVEN WITHOUT SIGNIFICANT
QPF IN THE MDLS...WE SHOULD BE ON THE LOOKOUT FOR HIGHER THAN
CURRENTLY EXPECTED TOTALS. LOWS WILL DIP INTO THE SINGLE DIGITS IN
THE N/W AND WIND CHILLS GO INTO THE SINGLE DIGITS BELOW ZERO
OVERNIGHT/THURS MORNING.

AS THE TROUGH AXIS SLIDES TO THE EAST ON THURS...WE SHOULD IMPROVE
WITH SNOW SHOWERS TAPERING OFF IN THE MORNING IN THE LAURELS. BUT
IT COULD TAKE ALL DAY FOR THEM TO LIFT OUT OF THE SNOW BELT. HAVE
EXTENDED THE TIME OF THE WINT WX ADVY FOR THE LAURELS INTO THE
MIDDLE OF THE DAY THURS TO MATCH TIMES WITH OUR LK EFF ADVY. MAXES
WILL BE ONLY 12-25F WHICH ARE ABOUT 15 TO 25 DEGS BELOW NORMAL FOR
THIS TIME OF YEAR.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
*IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS POSSIBLE WITH ARCTIC
 FRONT FRIDAY NIGHT-EARLY SATURDAY. FRIGID TEMPERATURES/DANGEROUS
 WIND CHILLS FOR VALENTINES WEEKEND.

POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND
NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND
ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE
NORTHEAST CONUS INTO NEXT WEEK.

THE FIRST SHOT OF COLD AIR ARRIVES ON THURSDAY WITH LAKE EFFECT
AND UPSLOPE SNOW SHOWERS TAPERING OFF THURSDAY NIGHT. LIGHT TO
MODERATE SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST
SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL
HIGHLANDS.

THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED
TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT
DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE
POSSIBLE WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO EARLY
SATURDAY.

MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO
ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT
INTO EARLY SUNDAY MORNING RANGE FROM AROUND 0F IN THE LOWER SUSQ.
VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES
COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL
RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA.

A SLOW MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT
WEEK...BUT WITH A POTENTIAL OVERRUNNING/WAA TYPE SNOW EVENT.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MINOR UPDATES TO 15Z TAF PACKAGE.

MAINLY VFR CIGS AND VSBYS WILL PREVAIL ACROSS THE SUSQ VALLEY TAF
SITES /KIPT...KMDT AND KLNS/ WITH HIGH END MVFR CIGS AND VFR TO
MVFR VSBYS AT KUNV AND KAOO.

THE POOREST FLYING CONDITIONS WILL CONTINUE TO BE AT KJST AND
KBFD FOR THE NEXT SEVERAL DAYS...WHERE CIGS AND VSBYS WILL BE
MAINLY IN THE MVFR TO UPPER IFR RANGE...WITH OCNL DIPS TO
LIFR/VLIFR IN LAKE EFFECT SNOW BANDS AND AREAS OF ENHANCED UPSLOPE
SNOWS.

FOR KUNV...KAOO...AND PERHAPS KIPT...EXPECT UP TO A FEW HOUR
PERIOD OF MORE FREQUENT SNOW SHOWERS LATE TODAY AND AFTER
SUNSET...AS A SECONDAY COLD FRONT PUSHES THROUGH THE AREA.

GUSTY WEST TO WNW WINDS WILL PREVAIL THIS AFTERNOON AND
THURSDAY...AVERAGING 12-15 KTS WITH GUSTS IN THE LOW-MID 20 KT
RANGE.

OUTLOOK...

THU...MVFR IN -SHSN W MTNS. VFR ELSEWHERE.
FRI...MVFR IN -SHSN...MAINLY LATE WITH STRONG COLD FRONT.
SAT...MVFR IN -SHSN W MTNS. VFR OTHERWISE. WINDY.
SUN...MVFR IN -SHSN IN W MTNS EARLY...OTHERWISE VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THURSDAY FOR PAZ005.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THURSDAY FOR PAZ004.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR PAZ024-033.

&&

$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...LAMBERT/MARTIN


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