679
FXUS61 KCTP 181633
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1133 AM 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 WEST. AN UPPER LOW WILL TRACK EAST
ACROSS THE AREA THURSDAY, THEN A MORE ZONAL FLOW PATTERN IS
ANTICIPATED INTO NEXT WEEKEND.
NEAR TERM /THROUGH TONIGHT/
RIDGING AT THE SFC AND DEEP LAYER SUBSIDENCE BENEATH THE
THERMALLY DIRECT LEFT REAR QUAD OF A STRONG ZONAL UPPER JET
SEGMENT WILL LEAD TO A MOSTLY SUNNY AND DRY DAY.
VERY COLD TEMPS WILL PREVAIL THOUGH WITH HIGH TEMPS (RANGING
FROM THE LOW TO MID TEENS OVER THE NORTHERN AND WESTERN HIGH
TERRAIN, TO THE MID AND UPPER 20S IN THE LOWER SUSQ VALLEY)
AVERAGING 15 TO 20 DEG F BELOW NORMAL FOR LATE FEB.
WNW WINDS WILL STILL BE MODERATELY GUSTY INTO THE 20S (KTS)
CREATING A BITE TO THE AIR WITH WIND CHILLS IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO.
EXPECT FAIR AND COLD CONDITIONS WITH DIMINISHING WINDS TONIGHT
UNDER AN ARRIVING SURFACE RIDGE. 2M TEMP PLUMES INDICATE
READINGS WILL BE JUST AS COLD AS THIS MORNING WITH MINTEMPS IN
THE SINGLE DIGITS TO LOW TEENS. HOWEVER, WIND CHILLS WON'T BE AS
COLD.
SHORT TERM /WEDNESDAY/
MODEL CONSENSUS KEEPS SOUTHERN STREAM DISTURBANCE FLAT AND SOUTH
OF THE REGION WEDNESDAY AND WEDNESDAY NIGHT, BRINGING ONLY
INCREASING CLOUDS TO SOUTHERN PA AND PERHAPS SOME PASSING
FLURRIES WED AFTN. THE NORTH WILL BE PARTLY CLOUDY AND
SEASONABLY COLD. HIGHS WILL ONLY REACH 15 TO 20F OVER THE
NORTHERN TIER, RANGING TO THE MID TO UPPER 20S SOUTH.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST LITTLE OR NO RISK OF
SIGNIFICANT SNOW THROUGH THE MIDDLE AND LATTER PART OF THE WEEK,
WITH MODEL CONSENSUS TRACKING A SURFACE LOW TOO FAR SOUTH/EAST
TO DIRECTLY IMPACT CENTRAL PA. WE HAVE LOWERED POPS TO 10-14 PCT
ACROSS THE SOUTH FOR THE DAY WED.
LIGHT SNOW SHOWERS AND FLURRIES ARE EXPECTED TO CROSS THE
ALLEGHENIES ON THURSDAY ASSOCIATED WITH THE PASSAGE A CLOSED
UPPER LOW ROLLING IN FROM THE MIDWEST AND LLVL DEFORMATION
BETWEEN IT AND THE OFFSHORE DEEPENING SFC LOW. ALTHOUGH DEEP
MOISTURE WILL BE LACKING, STRONG LARGE SCALE FORCING PRECEDING
THIS FEATURE SHOULD PRODUCE SNOW SHOWERS, ESPECIALLY OVER THE
ALLEGHENY PLATEAU DUE TO OROGRAPHIC FORCING. LATEST EPS MEAN QPF
SUPPORTS A LIGHT ACCUMULATION OF A COATING TO 1 INCH OVER THE W
MTNS, WITH LESSER AMOUNTS DOWNWIND (EAST) OF THE ALLEGHENIES.
BLUSTERY WEATHER LOOKS VERY LIKELY THU NIGHT/FRIDAY WITH LIGHT LAKE
EFFECT SNOW SHOWERS OVER THE ALLEGHENIES, AS THE UPPER LOW
EXITS THE REGION AND HIGH PRESSURE BUILDS IN FROM THE MIDWEST.
ENSEMBLE PLUMES SUPPORT LIGHT WINDS, SOME SUNSHINE AND GRADUALLY
MODERATING TEMPERATURES INTO NEXT WEEKEND WITH HIGHS NEAR
SEASONABLE LEVELS BY SUNDAY AND LIKELY ABOVE AVERAGE BY MONDAY.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
WNW SURFACE FLOW WITH SHALLOW MOISTURE ASCENDING THE ALLEGHENIES
WILL LEAD TO OCNL MVFR CIGS ACROSS THE WESTERN MTN AIRFIELDS
THROUGH THIS AFTERNOON AND TONIGHT WITH VFR CONDITIONS
ELSEWHERE.
WITH
RISING CLOUD HEIGHTS THROUGHOUT THIS TAF PACKAGE AND INTO
WEDNESDAY MORNING.
WNW WINDS WILL CONTINUE TO GUST BETWEEN 20-25KTS THROUGH THE DAY
TODAY AND LIKELY EARLY TONIGHT AS WELL BEFORE DECREASING BY
ABOUT 5-10KTS LATE TONIGHT INTO WED.
THE NEXT SYSTEM IS EXPECTED TO ARRIVE WEDNESDAY
AFTERNOON/EVENING. THE CENTER OF LOW PRESSURE IS CURRENTLY
PROJECTED TO PASS WELL SOUTH OF PENNSYLVANIA, BUT SOME GLANCING
SNOW SHOWERS WILL STILL LIKELY IMPACT AIRFIELDS WEDNESDAY NIGHT
INTO THURSDAY MAINLY IN THE SOUTHERN HALF OF PENNSYLVANIA.
OUTLOOK...
TUE...GENERALLY VFR AND BREEZY.
LATE WED NIGHT-THU...WIDESPREAD SNOW POSSIBLE, ESP S.
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/DEVOIR
SHORT TERM...LAMBERT/DEVOIR/FITZGERALD
LONG TERM...FITZGERALD/COLBERT
AVIATION...LAMBERT
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