Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 191242
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
742 AM EST WED NOV 19 2014

.SYNOPSIS...
A BRIEF REPRIEVE FROM THE EARLY ONSLAUGHT OF ARCTIC COLD WILL
OCCUR TODAY AHEAD OF A WEAK WAVE OF LOW PRESSURE THAT WILL MOVE
ACROSS THE UPPER GREAT LAKES AND BRING PERIODS OF LIGHT SNOW TO
THE NORTHWEST MOUNTAINS OF PENNSYLVANIA THIS AFTERNOON AND
EVENING. A COLD FRONT WILL PUSH EAST ACROSS THE STATE TONIGHT...
USHERING IN ANOTHER SHOT OF MUCH BELOW NORMAL TEMPERATURES AND
GUSTY WESTERLY WINDS FOR THURSDAY THROUGH FRIDAY NIGHT. MILDER
CONDITIONS WILL ARRIVE FOR THE SECOND HALF OF THE WEEKEND AS A
SOUTHWESTERLY FLOW OF AIR DEVELOPS ON SUNDAY. A STORM SYSTEM OVER
THE CENTRAL STATES WILL BRING A CHANCE OF RAIN SUNDAY NIGHT AND
MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SFC RIDGING WILL SLIDE EAST ACROSS THE REGION THIS MORNING
FOLLOWED BY A GRADUAL BACKING OF THE MEAN...SFC-850 MB FLOW TO THE
SOUTHWEST LATER THIS MORNING INTO TONIGHT.

A RATHER SMALL AREA OF BKN-OVC STRATO CU CLOUDS...AND MAINLY
FLURRIES WILL BE OVER THE LAUREL HIGHLANDS AND PORTIONS OF THE
SCENT MTNS THROUGH THE MID MORNING HOURS...POSSIBLY BRINGING A
LIGHT ADDITIONAL POWDERY COATING OF SNOW ON THE RIDGES ACROSS THE
REGION TO THE SOUTH OF INTERSTATE 80...AND GENERALLY WEST OF RT
219. ELSEWHERE...SKIES WILL REMAIN GENERALLY CLEAR.

TEMPS AT SUNRISE WILL VARY FROM THE SINGLE DIGITS ACROSS THE
MTNS...TO THE TEENS.

A 6-10 KT WEST TO SOUTHWESTERLY WIND WILL PRODUCE A WIND CHILL OF
AROUND 5 BELOW ACROSS THE MTNS...AND 5 TO 10 ABOVE ACROSS THE
CENTRAL MTNS AND SUSQ VALLEY.

RECORD LOWS FOR THIS DATE AT OUR PRIMARY CLIMATE SITES OF KIPT
/13F/ AND KMDT /18F/ APPEAR TO HAVE A CHANCE TO SQUEAK BY AND
STAND...THANKS TO THE WEST-SWRLY BREEZE KEEPING TEMPS FROM FALLING
MUCH MORE THAN ANOTHER DEG OR TWO OVER THE NEXT FEW HRS.

AFTERWARD...EXPECT ABUNDANT SUNSHINE IN MOST PLACES FOR THE LATE
MORNING HOURS.

A FAST-MOVING /ALBEIT RATHER FLAT/ UPPER TROUGH AND ASSOC CLIPPER
LOW WILL MOVE ACROSS THE UPPER GREAT LAKES LATE TODAY. LOW TO MID
LEVEL WAA AHEAD OF THIS FEATURE /AND ITS SOUTHEAST EXTENDING WARM
FRONT/ SHOULD SPREAD A GROWING SHIELD OF ALTOCU AND ALTOSTRATUS
ACROSS THE COMMONWEALTH THIS AFTERNOON. THE CLOUDS WILL THICKEN UP
ENOUGH TO SUPPORT AND AREA OF MAINLY LIGHT SNOW INTO THE NORTHWEST
QUARTER OF PENNSYLVANIA THIS AFTERNOON WITH AMOUNTS GENERALLY IN
THE 1-2 INCH RANGE BASED ON SREF MEAN SNOW ACCUMS. A FEW LOCATIONS
MAY SEE 3 INCHES BEFORE IT TRANSITIONS TO SNOW SHOWERS LATER
TONIGHT...BUT THE BULK OF THIS /FIRST ROUND/ OF SNOW WILL EQUATE
TO THE SUB- ADVISORY CATEGORY.

THE FORCING FOR THIS PERIOD OF STRATIFORM SNOW WILL BE RELATED TO
MDT TO STG WAA AT THE NOSE OF A PLUS 3 ST DEVIATION SWRLY LLJ AND
RIBBON OF 850 MB MOISTURE FLUX. THE BULK OF THE STEADIER /LIGHT/
SNOW WILL ALSO BE TIED TO THE BETTER OROGRAPHIC LIFT TO THE WEST
OF THE I-99/RT 220 CORRIDOR...WITH LITTLE MORE THAN FLURRIES
FURTHER TO THE SE.

TEMPS AND WIND CHILLS WILL NOT BE AS HARSH AS YESTERDAY IN THE
MODERATING SW FLOW AHEAD OF THE CLIPPER. HIGHS THIS AFTERNOON
SHOULD RANGE FROM THE 20S OVR MUCH OF THE AREA...TO AROUND
THE FREEZING MARK THROUGHOUT THE LOWER SUSQ VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
ANOTHER BLUSTERY DAY...AND BACK INTO THE DEEP FREEZE FOR THURSDAY
WITH FREQUENT SNOW SHOWERS ACROSS THE WESTERN MTNS/LAUREL
HIGHLANDS. THE SINGLE...INTENSE BAND OF LAKE EFFECT SNOW SHOULD
STAY MAINLY TO THE NORTH OF INTERSTATE 90 IN FAR NW PENN AND SW
NEW YORK THROUGH DUSK THURSDAY...BEFORE GRADUALLY SHIFTING SWD AND
MORE INLAND THURSDAY NIGHT.

ACROSS THE CENTRAL AND ERN ZONES...VARIABLE AMOUNTS OF STRATO CU
AND SCATTERED FLURRIES /AT MOST/ ARE EXPECTED.

TEMPS THURSDAY WILL START OUT IN THE L-M 20S ACROSS THE NW MTNS
AND LAURELS...BUT STAY STEADY OR SLOWLY FALL THROUGHOUT THE DAY
AS THE COLD AIR PUSHES EAST AND DEEPENS. HIGHS ELSEWHERE WILL
RANGE FROM THE LOW TO MID 30S ACROSS THE RIDGE AND VALLEY
REGION...TO AROUND 40F IN THE FAR SE INVOF KTHV AND KLNS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS THE MEAN WIND IN THE SFC-2 KM LAYER VEERS TO A MORE WNW
DIRECTION LATE THURSDAY INTO FRIDAY...THERE WILL BE A CHANCE FOR
MORE SNOW SHOWERS ACROSS THE NORTHWEST HALF OF THE CWA...WITH UP
TO SEVERAL INCHES LIKELY ACROSS THE NORTHWEST SNOWBELT WHERE LES
ADVISORIES MAY BE NEEDED WITH AN OUTSIDE SHOT AT SOME LOCATIONS
REACHING 12 HOUR WARNING CRITERIA OF 6 INCHES TO THE WEST OF KBFD.

MORE IN THE WAY OF SUNSHINE AND A WARMING TREND WILL OCCUR ON
SATURDAY...AS HIGH PRESSURE BUILDS NE AND BECOMES CENTERED OVER
THE MID ATLANTIC REGION.

MILDER TEMPERATURES FOR THE LATER PART OF THE WEEKEND
INTO EARLY NEXT WEEK...BUT SOME CHANCE OF SHOWERS INTO TUE.

DID UP POPS SOME...ESPECIALLY SUNDAY NIGHT...AS SURGE OF
MILDER AIR IS INDICATED TO WORK INTO THE AREA FROM THE SE.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SURFACE RIDGE OVER THE MID ATLANTIC REGION THIS MORNING IS KEEPING
CONDITIONS VFR AT MAJORITY OF TAF SITES. THE EXCEPTION IS KJST
WHERE OROGRAPHIC UPSLOPE FLOW CONTINUES TO PRODUCE MVFR
CONDITIONS WITH LIGHT SNOW SHOWERS /AND BREIFLY AT KAOO/. THESE
SHOULD IMPROVE TO VFR BY 15Z. GUSTINESS OF THE WIND HAS
DIMINISHED...BUT SPEEDS OF 10G20KT WILL BE COMMON TODAY AS WINDS
SHIFT TO THE SW.

BY THIS AFTERNOON...MID CLOUDS SPREAD INTO THE REGION WITH
RESTRICTIONS IN LIGHT SNOW DEVELOPING IN THE NW /MVFR TO SHORT
PERIOD OF IFR/ DUE TO LARGE SCALE FORCING ASSOCIATED WITH PASSAGE
OF A SHORTWAVE. BRIEF MVFR IMPACTS FROM -SHSN MAY REACH AN KAOO-
KUNV- KIPT LINE BY LATE AFTERNOON. MVFR CIGS THEN SPREAD INTO THE
WESTERN AND CENTRAL MTNS TONIGHT AS COLDER AIR FILTERS BACK IN
AND INVERSION LOWERS...WITH SCT SNOW SHOWERS BRINGING LOCAL
REDUCTIONS AROUND KBFD.

OUTLOOK...

WED...BLUSTERY AND VERY COLD WITH SNOW SHOWERS AND AREAS OF
REDUCED CIGS/VSBYS ACROSS THE NW AND CENTRAL MTNS.

THU...MAINLY DRY WITH VFR CONDITIONS. STILL A CHC OF SNOW SHOWERS
ACROSS THE NW.

FRI...CHANCE OF LIGHT SNOW AND POSS RESTRICTIONS MAINLY WEST/NORTH.

SAT...MAINLY VFR. MVFR POSSIBLE EARLY.

SUN...MAINLY VFR. A CHANCE OF RAIN SHOWERS.

&&

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

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR



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