Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 180530
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1230 AM EST THU DEC 18 2014

.SYNOPSIS...
NORTHWEST WINDS WILL KEEP SCATTERED SNOW SHOWERS GOING OVER THE
NORTH AND WEST THROUGH FRIDAY. A WEAK LOW PRESSURE AREA IS
EXPECTED TO MOVE WELL SOUTH OF THE REGION THIS WEEKEND. THERE ARE
INDICATIONS THAT THE WEATHER PATTERN COULD TURN MORE UNSETTLED FOR
NEXT WEEK.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
WINDS STILL GUSTY AND GRADIENT DOES NOT RELAX OVERNIGHT. SNOW
SHOWERS ARE NOT LIMITING THE VSBY MUCH AND ARE RATHER TRANSIENT.
ACCUMS SHOULD BE MINOR OVERNIGHT. TEMPS WON/T MOVE MUCH WITH
NEARLY-SOLID CLOUD DECK OVERHEAD EXPECTED TO STAY IN PLACE. SOME
BREAKS ARE TRING TO APPEAR...BUT THEY SHOULD NOT GET ALL THAT
LARGE BEFORE DAYBREAK.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM FRIDAY/...
COLD AIR WILL STAY IN PLACE ACROSS THE FCST AREA THURSDAY INTO
FRIDAY.

THURSDAY...WINDS AT THE SFC AND ALOFT WILL VEER JUST SLIGHTLY TO
THE NORTHWEST. SPEEDS OF 10-15 MPH AND GUSTS INTO THE L20S ARE
POSSIBLE OVER THE MOUNTAINS. LITTLE OF NO CHANGE IN THE BLANKET OF
STRATUS AND STRATOCU CLOUDS IS EXPECTED THURSDAY AND THU
NIGHT...AND THE RELATIVELY SHALLOW COLD AIR BLOWING OVER THE LOWER
GLAKES WILL CREATE MORE SHSN ACROSS THE NRN AND WRN MTNS.

ACCUMULATIONS WILL BE MINOR...AND CONFINED TO THE FAR NW AND VERY
HIGHEST ELEVATIONS. AS STATED BY PREVIOUS SHIFTS NO MORE THAN 2
INCHES IS EXPECTED THROUGHOUT THE SNOWBELT OF NW WARREN COUNTY ON
THE HIGH END...SO NO LES ADVISORIES PLANNED ATTM. GLIMPSES OF
SUN MAY DEVELOP AGAIN ACROSS THE LOWER SUSQ...NUDGING TEMPS INTO
THE LOWER 40S /NEAR NORMAL FOR MID DEC/. MAX TEMPS ACROSS THE NRN
AND WRN MTNS WILL BE IN THE U20S TO L30S.

SIMILAR TEMPS AND SKY COVER EXPECTED AGAIN FOR THU NIGHT WITH
ISOLATED TO SCTD MTN SNOW SHOWERS. LITTLE IN THE WAY OF
ADDITIONAL SNOW ACCUM IS EXPECTED THOUGH AS MOISTURE WILL
CONTINUE TO BE QUITE SHALLOW WITH THE SUBSIDENCE INVERSION BASE
AOB 5 KFT AGL. A FEW HIGHLY LOCALIZED AMOUNTS IN THE 2-3 INCH
RANGE ARE POSSIBLE ACROSS THE FAVORED PERENNIAL SNOWBELT OF WARREN
COUNTY DURING THE 24 HOUR PERIOD ENDING 12Z FRI.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE PATTERN WILL REMAIN SEASONABLY COLD AND BRISK THROUGH THE END
OF THE WEEK. LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH
MIGRATING EASTWARD FROM THE UPPER MIDWEST ACROSS ONTARIO/QUEBEC
SHOULD BRING AN END TO NUISANCE/MINOR SNOW SHOWER ACTIVITY AND
LINGERING FLURRIES OVER THE NW ALLEGHENIES BY FRI NGT. CLEAR SKIES
AND CALM/LIGHT WINDS SHOULD ALLOW MIN TEMPS TO DIP INTO THE TEENS
IN THE NORTHERN MTNS SATURDAY MORNING.

CONCERNING THE WEEKEND SYSTEM...

HOPES FOR A SIGNIFICANT STORM THIS WEEKEND CONTINUE TO FADE WITH
THE LATEST MODELS CONTINUING TO SHOW A MUCH WEAKER/SUPPRESSED AND
DISJOINTED SYSTEM AS THE CONSENSUS SOLUTION. IN ADDITION..THE
RISK FOR ACCUMULATING LIGHT SNOW HAS ALSO NOTABLY DECREASED...BUT
NOT TOTALLY EVAPORATED. THAT SAID THERE IS STILL A NON-TRIVIAL
CHANCE THAT MOST PRECIP REMAINS SOUTH OF PA AND THE WEEKEND TURNS
OUT DRY FOR MOST LOCATIONS. EARLY WEEK MODEL SIMULATIONS FOR A
MAJOR STORM HAVE ALL BUT TRENDED TO A VIRTUAL NON EVENT FOR OUR
AREA.

THE PROGRESSIVE SPLIT STREAM ENERGY ALOFT MOVING EAST FROM THE
MID MS VLY NEVER REALLY ORGANIZES AS IT ATTEMPTS TO OVERRUN A
RETREATING AREA OF MODESTLY STRONG HP/RIDGING OVER THE NORTHEAST
AND EASTERN CANADA. AS SUCH DOWNPLAYED PCPN POTENTIAL AND TRIMMED
POPS BACK BY 10-20 PCT. THE NEW WRINKLE IN THIS FORECAST CYCLE IS
FOR A SECOND PIECE OF ENERGY /WHAT APPEARS TO BE THE MAIN SFC LOW/
LIFTING NORTH FROM NEAR THE FL/GA COAST AND TRACKING UP/OFFSHORE
THE EAST COAST SUN THRU TUE.

THE SPLIT FLOW PATTERN OVER THE CONUS IS EXPECTED TO BECOME HIGHLY
AMPLIFIED WITH A VERY DEEP NEGATIVELY TILTED TROUGH EVOLVING EAST
OF THE ROCKIES...LIKELY SPAWNING AN INTENSE SFC LOW OVER THE
GREAT LAKES/MID ATLANTIC/NORTHEAST REGIONS AROUND THE CHRISTMAS
EVE TIME FRAME. FOR WHAT ITS WORTH...BOTH THE 17/12Z GFS AND EC
ARE FORECASTING A RECORD LOW MSLP SUB 970MB CYCLONE INVOF LAKE
HURON AT 00Z ON 25 DEC. THIS SYSTEM WILL LIKELY GATHER MORE AND
MORE ATTENTION AS WE MOVE CLOSER TO THE HOLIDAY. THE GOOD NEWS FOR
TRAVELERS/BAD NEWS FOR SNOW CROWS IS THAT CURRENT PROJECTIONS
WOULD PLACE CENTRAL PA INITIALLY IN THE "WARM" SIDE OF THE DEEP
STORM FAVORING RAIN VS. SNOW. IT ALSO LOOKS QUITE WINDY ASSUMING
THE DEEP LOW VERIFIES.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
WIDESPREAD STRATO CU AND PERSISTENT MVFR TO IFR CIGS WITH
ISOLATED-SCATTERED AND GENERALLY BRIEF MVFR TO IFR VSBYS IN SNOW
SHOWERS WILL OCCUR ACROSS THE NW MTNS AND LAUREL HIGHLANDS /INVOF
KBFD AND KJST/ TONIGHT INTO THE MORNING HOURS. CONDITIONS ACROSS
THE CENTRAL MTNS WILL VARY BETWEEN LOW END VFR...AND MVFR CIGS.

GUSTY WEST TO WNW WINDS /UP AROUND 25 KTS AT TIMES/ WILL ADD SOME
MECHANICAL TURBULENCE DURING TAKEOFF AND FAP TO REGIONAL AIRFIELDS
THIS EVENING THROUGH THURSDAY. VFR CIGS AND VSBYS SHOULD CONTINUE
OVERNIGHT THROUGH THE EASTERN TAF SITES.

OUTLOOK...

THU-FRI...MVFR CIGS POSS NW. OTHERWISE NO SIG WX EXPECTED.

SAT-SUN...LIGHT SNOW/REDUCED VSBY POSSIBLE ...MAINLY ALONG THE MD
BORDER.

MONDAY...MAINLY VFR. HOWEVER...AREAS OF MVFR STRATO CU ARE
POSSIBLE IN DEVELOPING SERLY LOW LEVEL FLOW.

&&

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

&&

$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU


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