211
FXUS61 KCTP 210812
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
312 AM EST FRI FEB 21 2025
SYNOPSIS
* GUSTY NORTHWEST WINDS CONTINUE TODAY AS UPSLOPE SNOW SHOWERS
GRADUALLY TAPER OFF.
* DRY CONDITIONS PREVAIL THIS WEEKEND WITH HIGH PRESSURE
BUILDING IN AND TEMPERATURES TRENDING UP.
* A COUPLE SYSTEMS WILL BRING RAIN - AND PERHAPS SOME SNOW -
DURING THE LAST WEEK IN FEBRUARY.
NEAR TERM /THROUGH TODAY/
A COLD NORTHWEST FLOW ORIGINATING OVER LK HURON CONTINUES TO
PRODUCE LIGHT, LAKE-ENHANCED SNOW/FLURRIES OVER THE ALLEGHENIES
EARLY THIS MORNING. VISIBILITIES AT 07Z ARE GENERALLY >5SM, BUT
AS LOW AS 1/2SM ON LAUREL RIDGE, WHERE OROGRAPHIC FORCING IS THE
GREATEST. MODEL QPF SUPPORT UP TO AN HALF INCH OF ADDITIONAL
ACCUMULATION ON LAUREL RIDGE EARLY THIS MORNING, WITH NO MORE
THAN A DUSTING ELSEWHERE. LITTLE CHANGE IN TEMPS ARE EXPECTED
FOR THE BALANCE OF THE NIGHT DUE TO AN ACTIVE BREEZE AND NEARLY
NEUTRAL TEMP ADVECTION. EXPECT READINGS AT DAWN TO RANGE FROM
THE LOW TEENS OVER THE N MTNS, TO AROUND 20 OVER THE LOWER SUSQ
VALLEY.
FALLING INVERSION HEIGHTS UPON THE APPROACH OF HIGH PRESSURE
WILL CAUSE ANY LINGERING LIGHT SNOW SHOWERS/FLURRIES OVER THE NW
MTNS AND LAURELS TO TAPER OFF TODAY, WITH NO ADDITIONAL
ACCUMULATION EXPECTED. A TIGHT GRADIENT BETWEEN EXPANSIVE HIGH
PRESSURE IN THE MISS VALLEY AND AN INTENSE LOW SOUTHEAST OF
NEWFOUNDLAND WILL CONTINUE TO PRODUCE FAIRLY GUSTY NORTHWEST
WINDS TODAY. BUFKIT SOUNDINGS SUPPORT GUSTS A BIT ABOVE NBM
GUIDANCE WITH FREQUENT GUSTS AROUND 25KTS TODAY.
MODEL RH PROFILES INDICATE LAKE EFFECT STRATOCU WILL BE
PERSISTENT TODAY ACROSS THE ALLEGHENIES, WHILE SUBSIDENCE TO
THE LEE OF THE MOUNTAINS SHOULD RESULT IN PARTLY TO MOSTLY SUNNY
SKIES IN THE SUSQ VALLEY. MODERATING TEMPS ARE EXPECTED TODAY
WITH THE DEPARTURE OF THE UPPER LOW. MIXING DOWN 900MB TEMPS OF
-10C TO -13C YIELDS EXPECTED HIGHS RANGING FROM AROUND 20F OVER THE
N MTNS, TO THE LOW 30S IN THE LOWER SUSQ VALLEY.
SHORT TERM /TONIGHT THROUGH SUNDAY/
SURFACE HIGH PRESSURE OVER THE OHIO VALLEY WILL NOSE INTO PA
TONIGHT, PROVIDING THE REGION WITH FAIR/COLD CONDITIONS AND
RELATIVELY LIGHT WINDS. MODEL SOUNDINGS CONTINUE TO INDICATE LOW
LEVEL MOISTURE TRAPPED BENEATH A STRONG SUBSIDENCE INVERSION
WILL RESULT IN LINGERING LOW CLOUDS OVER THE ALLEGHENIES
TONIGHT, WHILE MAINLY CLEAR SKIES ARE ANTICIPATED TO THE LEE
(EAST) OF THE MOUNTAINS.
HIGH PRESSURE IS PROGGED TO PASS SOUTH OF PA THIS WEEKEND, RESULTING
IN FAIR WEATHER, WITH A WEST-SOUTHWEST FLOW IMPORTING MILDER
AIR INTO PA. A PAIR OF MOISTURE-STARVED SHORTWAVES SHOULD
TRAVERSE THE REGION, ONE SAT PM AND ANOTHER SUN PM. ALTHOUGH NO
PRECIPITATION IS EXPECTED FROM THESE SYSTEMS, COLD TEMPS ALOFT
SHOULD RESULT IN A DECENT AMOUNT OF AFTERNOON CUMULUS OVER THE
NORTHERN TIER OF THE STATE, ESPECIALLY SUNDAY.
GEFS 2M TEMP ANOMALIES SUGGEST READINGS THIS WEEKEND WILL GET
BACK TO NEAR NORMAL BY SUNDAY, WITH HIGHS RANGING FROM THE LOW
30S OVER THE N MTNS, TO THE MID 40S IN THE LOWER SUSQ VALLEY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
LATE EVENING UPDATE.
NOT A LOT OF CHANGE TO THE EXTENDED PART OF THE FORECAST.
RAN FORECAST BUILDER, SOME MINOR CHANGES TO THE EARLIER
GRIDS. MAIN THING WAS A BIT WETTER LATER ON MONDAY AND COOLER
LATER NEXT WEEK.
WHILE WE GET A BREAK FROM THE COLD WEATHER THIS WEEKEND INTO
THE FIRST PART OF NEXT WEEK, THE LARGE SCALE WEATHER PATTERN
REMAINS SIMILAR TO MUCH OF THE WINTER SO FAR. A LARGE SCALE
TROUGH IS LIKELY TO BE IN PLACE ACROSS THE EAST BY EARLY
MARCH, WHICH WOULD SUPPORT BELOW NORMAL TEMPERATURES AGAIN.
ANYWAY, EARLIER INFORMATION BELOW.
KEY TAKEAWAYS: MONDAY, FEBRUARY 24 - THURSDAY, FEBRUARY 27
------------------------------------------------------------
*WARMING TREND TO NEAR/ABOVE HISTORICAL AVERAGES TO END FEBRUARY
*QUICK MOVING SYSTEMS BRING PASSING RAIN/SNOW SHOWERS MON-TUE
*HIGHEST PROBABILITY & CONFIDENCE IN WIDESPREAD PRECIP THU-FRI
A PAIR OF FAST MOVING NORTHERN STREAM SHORTWAVES WILL BRING
PASSING RAIN/SNOW SHOWERS EARLY NEXT WEEK. SNOW SHOWERS ARE
MOST LIKELY OVER THE HIGHER ELEVATIONS WITH RAIN SHOWERS IN THE
VALLEYS. MAX POPS ARE ON TUESDAY BASED ON NBM AND EC/CMC/GFS
LIKELY FOLLOWED BY SOME LINGERING LIGHT PRECIP DOWNWIND OF LAKE
ERIE AND OVER THE WESTERN ALLEGHENIES/LAUREL HIGHLANDS TUE NIGHT
INTO EARLY WEDNESDAY. THE LATEST DETERMINISTIC, ENSEMBLE, AND
MACHINE LEARNING MODELS SHOW A LARGER STORM SYSTEM IMPACTING THE
REGION IN THE THURSDAY/FRIDAY TIMEFRAME WITH THE POTENTIAL FOR
RAIN AND SNOW. WE HAVE ABOVE AVERAGE CONFIDENCE IN MEASURABLE
PRECIP IN THIS TIME WINDOW (STICKING WITH NBM MAX POP 65-80%),
BUT DETAILS CONCERNING WINTER WX/PTYPE/ACCUMULATION ARE STILL
NOT CLEAR AT THIS RANGE. SOME LOCATIONS IN THE LOWER SUSQUEHANNA
VALLEY COULD REACH THE 50F MARK FOR 4 CONSECUTIVE DAYS MON-THU.
AVIATION /07Z FRIDAY THROUGH TUESDAY/
LIGHT TO LOCALLY MODERATE SNOW SHOWERS AND BANDS CONTINUE
ACROSS CENTRAL AND WESTERN PA DOWNWIND OF THE GREAT LAKES. VSBYS
HAVE GENERALLY IMPROVED WITH FEWER SITES DROPPING BELOW 1 SM AS
OF 00Z. UPSLOPE AND LAKE ENHANCED SNOW SHOWERS WILL CONTINUE
THROUGH MUCH OF THE OVERNIGHT FOR THE LAUREL HIGHLANDS AND NW
MTNS (KJST AND KBFD). CIGS AT THESE AIRFIELDS WILL LIKELY FALL
BELOW 1000 FT BY 04-06Z FRI WITH MVFR TO IFR CIGS HOLDING ON
THERE INTO MUCH OF THE DAY FRIDAY. A PERIOD OF MVFR CIGS IS
ALSO POSSIBLE AT IPT, AOO AND UNV (60% CHC) PARTICULARLY
BETWEEN 02Z AND 15Z FRI BEFORE IMPROVEMENTS FRI AFTERNOON.
AIRFIELDS IN THE LOWER SUSQ VALLEY WILL LIKELY REMAIN VFR WITH
LESS THAN A 40% CHC OF MVFR CIGS BRIEFLY TONIGHT. THE WIND WILL
BEGIN TO DIMINISH FRIDAY AS WE GET CLOSER TO SUNSET, BUT SOME
G20KT LINGER FRI EVENING.
OUTLOOK...
FRI NIGHT-SUN...VFR/NO SIG WX.
MON...RAIN AND SNOW SHOWERS DEVELOPING IN THE AFTERNOON NW.
CTP WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ033.
SYNOPSIS...BANGHOFF
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/BANGHOFF
LONG TERM...STEINBUGL/MARTIN
AVIATION...DANGELO/COLBERT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page