Area Forecast Discussion
Issued by NWS State College, PA

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646
FXUS61 KCTP 131513
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1013 AM EST SAT FEB 13 2016

.SYNOPSIS...
POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE
WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL
SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS
EASTERN PA ON TUESDAY.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...

ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY.
TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES.
STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE
NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL
PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF
THE REGION TODAY INTO SUNDAY.

WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER
UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO.

RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE
BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS
BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT
SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING.

MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER
AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM
TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN
THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A
PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS
KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND
IN NORTHWESTERN PA THIS EVENING.

COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING
SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 7 PM SUNDAY/...

MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF
SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE
FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND
MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME
AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL
COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS.

THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED
OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND
THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD
VALENTINES AT LEAST OUTDOORS.

THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING
CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO
MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW
SUNDAY LIKELY WILL BE EARLY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
 WEEK.

BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.

WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.

NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
ARCTIC AIR MASS POURING INTO THE REGION EARLY THIS MORNING...
CURRENTLY ACCOMPANIED BY GUSTY NW WINDS OF 15G25KTS. WINDS WILL
PICK UP FURTHER DURING THE DAY...WITH GUSTS APPROACHING
40-45KTS...BEFORE GRADUALLY DIMINISHING TONIGHT.

RADAR AT 11Z SHOWING SCT SHSN ACCOMPANYING ARRIVAL OF ARCTIC AIR
MASS ACROSS WESTERN/CENTRAL MTNS. ARRIVAL OF LOW PWAT AIR MASS
SHOULD CAUSE MOST OF THESE SNOW SHOWERS TO DISSIPATE EARLY IN THE
DAY. SNOW SHOWERS WILL LINGER OVER WARREN COUNTY /WITH POSSIBLE
BRIEF EXCURSIONS TOWARD KBFD/ WITH MORE PERSISTENT SNOW
SHOWERS/BANDS ASSOC WITH LK HURON CONNECTION TO LAST THRU THE DAY
ACROSS THE LAUREL HIGHLANDS /KJST/. RESTRICTIONS WILL PERSIST OVER
WESTERN HIGHER TERRAIN. BUT WITH DOWNSLOPE FLOW KICKING IN FOR
CENTRAL MTNS AND SE...VFR WILL BE THE GENERAL RULE - WITH JUST A
CHANCE FOR SOME SCT SNOW BANDS TO CREEP INTO PORTIONS OF THE
CENTRAL MTNS LATE DAY.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.

MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN AND/OR
SNOW IN THE SE. WIDESPREAD RESTRICTIONS CONTINUE. LLWS POSS SE.

WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017-
018-024-033.
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028-
034>036-045-046-049>053-056>059-063>066.
WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059-
063>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...RXR



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