132
FXUS61 KCTP 182019
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
319 PM EST TUE FEB 18 2025
SYNOPSIS
AN ELONGATED UPPER TROUGH WILL REMAIN JUST NORTH OF
PENNSYLVANIA THE NEXT COUPLE OF DAYS, AS SURFACE RIDGING
NOSES INTO THE STATE FROM THE MIDWEST AND OHIO VALLEY.
AN UPPER LOW WILL TRACK EAST ACROSS THE COMMONWEALTH ON
THURSDAY BRINGING PERIODS OF LIGHT SNOW, THEN A MORE ZONAL
FLOW PATTERN IS ANTICIPATED INTO NEXT WEEKEND.
NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
RIDGING AT THE SFC AND DEEP LAYER SUBSIDENCE BENEATH THE
THERMALLY DIRECT LEFT REAR QUAD OF A STRONG ZONAL UPPER JET
SEGMENT GAVE US A PARTLY TO MOSTLY SUNNY DRY AND COLD DAY WITH A
MODERATELY GUSTY NW WIND UP TO AROUND 25 KTS AT TIMES.
SUSTAINED WIND AND GUSTS WILL DECREASE BY 5 TO 10 KTS TONIGHT,
BUT WILL STILL BE ENOUGH TO COMBINE WITH THE VERY COLD TEMPS TO
PUSH WIND CHILLS DOWN INTO THE -5 TO -10F RANGE ACROSS THE
LAUREL HIGHLANDS AND NW MTNS, AND INTO SINGLE DIGITS ABOVE
ZERO OVER THE SUSQUEHANNA VALLEY AND ADJACENT SOUTH-CENTRAL
ZONES.
ACTUAL LOW TEMPS WILL VARY FROM THE LOWER SINGLE DIGITS OVER
THE NORTHERN AND WESTERN MTNS TO THE LOW TEENS IN THE SE.
SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/
MODEL SOUNDINGS VIA BUFKIT AND HREF RH FIELDS SHOW PLENTY OF
THICK MID AND HIGH CLOUDS ADVECTING ENE ACROSS THE REGION
WEDNESDAY AND WED NIGHT WITH AT MOST SOME INTERMITTENT VERY
LIGHT SNOW OR FLURRIES POSSIBLE ACROSS THE WESTERN MTNS TOWARD
DUSK AS CLOUD BASES WILL BE MAINLY AOA 6-8 KFT AGL.
NW WINDS OF 7 TO 15 KTS IN THE MORNING WILL VEER AROUND TO THE
NORTH LATE AND DECREASE TO 6 KTS OR LESS.
TEMPS WILL INCREASE BY ONLY 3-4 DEG F COMPARED TO TUESDAY, BUT
WIND CHILL VALUES WILL MODERATE BY 10-15 DEG F DOD AS WE HEAD
INTO THE AFTERNOON. HIGHS WED WILL ONLY REACH 15 TO 20F OVER
THE NORTHERN TIER, RANGING TO THE MID TO UPPER 20S SOUTH.
LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/
MOSTLY CLOUDY AND COLD WEDNESDAY NIGHT WITH LOW TEMPS IN THE
+SINGLE DIGITS AND TEENS OR 5 TO 10 DEGREES BELOW LATE FEBRUARY
CLIMO.
DEEP 500MB CLOSED LOW (-2 TO -3SD) WILL TRACK TO THE SOUTH OF
PA BETWEEN 20/0000UTC AND 21/0000UTC. DESPITE LIMITED MOISTURE,
LARGE SCALE FORCING AND HEIGHT FALLS ASSOCIATED WITH THE DEEP
MID/UPPER LEVEL LOW SHOULD GENERATE ENOUGH LIFT TO PRODUCE SOME
LIGHT/FLUFFY (DRY) SNOW ACCUMULATION (SLR >18-20:1) ACROSS
CENTRAL PA ON THURSDAY. INCREASING NW FLOW INTO THURSDAY NIGHT
WILL ENHANCE UPSLOPE SNOW SHOWER ACTIVITY OVER THE WESTERN AND
NORTHERN ALLEGHENIES WITH UP TO 3 INCHES OF POWDER IN THE
PERENNIAL SNOWBELTS, SUMMITS, AND SKI RESORTS TO THE WEST OF
US-219 ENDING 12Z FRIDAY. THURSDAY WILL BE WINDY AND QUITE COLD
EVEN BY LATE FEBRUARY STANDARDS WITH MAX TEMPS 15 TO 25 DEGREES
BELOW THE HISTORICAL AVERAGE AND MINIMUM WIND CHILLS -10 TO +10F.
BLUSTERY NW FLOW CONTINUES INTO EARLY FRIDAY ALONG WITH SNOW
SHOWERS/FLURRIES OVER THE ALLEGHENY PLATEAU. THE WIND WILL
GRADUALLY DIMINISH INTO FRIDAY NIGHT AS HIGH PRESSURE RIDGE
SLIDES INTO THE REGION. WE WERE KEEN TO FOLLOW THE USUAL
PLAYBOOK ADJUSTMENTS VS. NBM WHICH INCLUDED HIGHER POPS, QPF,
SNOWFALL, AND WIND/WIND GUSTS FOR THU AND FRI. SNOWFALL AND MAX
WIND GUSTS ARE PROJECTED TO REMAIN BELOW ADVISORY CRITERIA, BUT
COULD STILL IMPACT TRAVEL ESPECIALLY OVER THE HIGHER ELEVATIONS.
THE ARCTIC PUNCH WILL MODERATE BY THE WEEKEND WITH TEMPERATURES
TRENDING WARMER/CLOSER TO LONG TERM AVERAGES SATURDAY-TUESDAY.
MODEL VARIABILITY WITH FAST MOVING/MOISTURE LACKING CLIPPER
TYPE DISTURBANCES IN THE NORTHERN STREAM WILL FAVOR LOW POPS ON
BALANCE THIS WEEKEND INTO EARLY NEXT WEEK.
AVIATION /20Z TUESDAY THROUGH SUNDAY/
WNW SURFACE FLOW WITH SHALLOW MOISTURE ASCENDING THE ALLEGHENIES
WILL LEAD TO SCT-OCNLY BKN HIGH BASED STRATO CU (040-050 AGL)
LATE THIS AFTERNOON, WITH MVFR CIGS LIKELY FORMING TONIGHT
ACROSS THE WESTERN MTN AIRFIELDS THROUGH TONIGHT. VFR WILL
PERSIST ELSEWHERE FROM LATE TODAY THROUGH LATE WEDNESDAY.
WNW WINDS WILL CONTINUE TO GUST BETWEEN 20-25KTS THROUGH THE
REST OF THE DAY TODAY AND LIKELY EARLY TONIGHT, BEFORE
DECREASING BY ABOUT 5-10KTS LATE TONIGHT INTO WED.
THE NEXT WEATHER SYSTEM IS EXPECTED TO ARRIVE THURSDAY IN THE
FORM OF A RATHER DEEP UPPER DRIFTING EAST ACROSS THE STATE.
THICK CLOUD COVER WITH LOWERING BASES AND LIKELY SOME PERIODS
OF LIGHT SNOW AND MVFR TO IFR CIGS AND VSBYS WILL OCCUR, WHILE
THE CENTER OF SFC LOW PRESSURE AND STEADY/HEAVIER SNOW IS STILL
PROJECTED TO PASS WELL SOUTH OF PENNSYLVANIA.
OUTLOOK...
WED...GENERALLY VFR, THICK MID LEVEL CLOUDS. AN 8-15KT BREEZE
FROM THE NW IN THE MORNING THEN DIMINISHING WIND.
LATE WED NIGHT-THU...WIDESPREAD LIGHT SNOW POSSIBLE.
FRI...POST STORM GUSTY W-NW WINDS. REDUCED CIGS LIKELY BFD/JST.
SAT-SUN...VFR AND DRY.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT
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