063
FXUS61 KCTP 211921
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
221 PM 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 FAST-MOVING AND MOISTURE-POOR SYSTEMS COULD BRING
RAIN AND PERHAPS SOME FLEETING SNOW SHOWERS DURING THE LAST
WEEK IN FEBRUARY.
NEAR TERM /UNTIL 8 PM THIS EVENING/
CLOUDS AND LIGHT SNOW SHOWERS CONTINUE TO OVERACHIEVE ACROSS
THE AREA, BUT BIG BREAKS ARE STARTING TO APPEAR IN THE SOUTH-
CENTRAL COUNTIES AND N OF IPT, TOO. AMPLE MOISTURE FLOW OFF THE
LAKES IS ALSO GOING TO CONTINUE FOR A WHILE JUDING BY UPSTREAM
CLOUDINESS AND THE SLOWLY SINKING INVERSION. THE TREND IS,
THEREFORE, TO LINGER THE SHSN AND CLOUDS A BIT LONGER THRU THE
AFTN, AND EVEN VERY EARLY EVENING IN THE W. NO CHANGES TO TEMPS.
PREV...
A COLD NORTHWEST FLOW ORIGINATING OVER LK HURON CONTINUES TO
PRODUCE LIGHT, LAKE-ENHANCED SNOW/FLURRIES OVER THE ALLEGHENIES
EARLY THIS MORNING. MODEL QPF SUPPORT UP TO AN HALF INCH OF
ADDITIONAL ACCUMULATION ON LAUREL RIDGE EARLY THIS MORNING, WITH
NO MORE THAN A DUSTING ELSEWHERE. 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 THIS AFTERNOON, 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 /8 PM THIS EVENING THROUGH SUNDAY NIGHT/
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 /MONDAY THROUGH THURSDAY/
LOW PRESSURE STATIONED TO THE NORTH OF CENTRAL PENNSYLVANIA ON
MONDAY HAD RECENTLY KEPT MENTIONS OF PRECIPITATION; HOWEVER,
DRIER AIR AND SLIGHTLY FURTHER NORTH PROGRESSION IN MODEL
GUIDANCE HAS NIXED PRECIPITATION MENTIONS ON MONDAY. IF ANY
PRECIPITATION IS TO MAKE WAY INTO CENTRAL PENNSYLVANIA, IT WOULD
BE LIMITED TO THE NORTHERN TIER IN THE FORM OF A RAIN/SNOW MIX
TO RAIN AND ANY ACCUMULATIONS WOULD BE LIGHT. SLIGHTLY BETTER
CHANCE OF PRECIPITATION COMES ON TUESDAY WITH A SHORTWAVE
BRINGING ENHANCED LIFT WITH SLIGHTLY BETTER (BUT STILL NOT
OPTIMAL) MOISTURE, THUS HAVE KEPT CHANCES ON TUESDAY. MILD
TEMPERATURES FOR THE END OF FEBRUARY ARE EXPECTED ON TUESDAY,
WHICH WILL PROMOTE MAINLY RAIN SHOWERS; HOWEVER, MODEL GUIDANCE
(AND SOUNDINGS) HAVE OUTLINED SOME POTENTIAL FOR WET SNOW
ESPECIALLY EARLY TUESDAY MORNING AND TUESDAY EVENING. DRY
CONDITIONS ARE EXPECTED TO PREVAIL EARLY WEDNESDAY MORNING AND
LAST THROUGH MUCH OF THE DAY AS THE BEST FORCING/MOISTURE MOVES
FURTHER AWAY FROM THE FORECAST AREA.
LATEST MODEL GUIDANCE CONTINUES TO OUTLINE POTENTIAL FOR A
LARGER STORM SYSTEM IMPACTING THE REGION IN THE THURSDAY/FRIDAY
TIMEFRAME WITH THE POTENTIAL FOR RAIN AND SNOW, AND POTENTIALLY
EVEN A WINTRY MIX (ALTHOUGH CONFIDENCE REMAINS TOO LOW AT THIS
TIME TO MENTION ANYTHING OUTSIDE OF RAIN/SNOW) ACROSS PORTIONS
OF THE AREA. RAIN AT ONSET THURSDAY SEEMS TO BE VERY PLAUSIBLE
WITH THE TRANSITION INTO A WINTRY MIX COMING THURSDAY EVENING
INTO FRIDAY. TIMING/CONFIDENCE ON MEASURABLE PRECIPITATION
REMAINS FAIRLY CLOSE TO PREVIOUS FORECAST CYCLES.
AVIATION /20Z FRIDAY THROUGH WEDNESDAY/
LINGERING SNOW SHOWERS ACROSS THE WESTERN HALF OF THE AIRSPACE,
MAINLY INFLUENCING CONDITIONS AT BFD/JST AS OF 18Z FRIDAY
OBSERVATIONS. RECENT OBSERVATIONS ALSO OUTLINE -SHSN AT UNV/AOO;
HOWEVER, DRIER AIR IN THE LOWER LEVELS OBSERVED BY DEW POINT
DEPRESSIONS HAVE LIMITED VISIBILITY/CEILING RESTRICTIONS WITH
VFR CONTINUING TO PREVAIL. AT IPT/MDT/LNS, CURRENT CONDITIONS
PREVAIL AT VFR WITH HIGH (~80-90%) CONFIDENCE IN VFR CONDITIONS
PREVAILING THROUGH 18Z SATURDAY, WITH BREEZY WINDS BEING THE
MAIN CONCERN THROUGHOUT THE TAF PERIOD, MAINLY BETWEEN 18Z-23Z
FRIDAY.
LIGHT SNOW IS EXPECTED TO CONTINUE TO BRING RESTRICTIONS AT BFD
(~90-100% CONFIDENCE) AND JST (~40-50%) CONFIDENCE THROUGH 22Z
FRIDAY, WITH SOME SIGNALS IN LOWER CEILINGS CONTINUING AT BFD
IN RECENT HREF/RAP MODEL GUIDANCE. THESE TRENDS ARE ALSO FAIRLY
WELL-RESOLVED IN GLAMP GUIDANCE, WHILE GLAMP GUIDANCE SHOWS
SLIGHTLY MORE DISAGREEMENT AT JST, THUS LOWER CONFIDENCE IN THE
TAF AT JST. THERE WILL ALSO BE SOME POTENTIAL AT UNV TO HAVE
PERIODS OF MVFR CEILINGS BETWEEN 18-22Z; HOWEVER, THIS REMAINS A
LOWER PROBABILITY SOLUTION. MODEL SOUNDINGS CONTINUE TO OUTLINE
MODEST SATURATION IN THE LOWER LEVELS AT BFD, THUS MODERATE-TO-
HIGH (~50-70%) CONFIDENCE IN MVFR CEILINGS CONTINUING THROUGH
18Z SATURDAY WITH GUIDANCE STARTING TO OUTLINE IFR/LIFR
CONDITIONS IN THE OVERNIGHT PERIOD. HIGH CONFIDENCE IN IFR
CONDITIONS AT BFD BETWEEN 06-12Z SATURDAY, WITH INCREASING
SIGNALS OF LIFR IN THE 10-12Z TIMEFRAME. AT JST, MVFR CONTINUES
TO BE THE MAIN RESTRICTION EXPECTED THIS EVENING WITH IFR
CONDITIONS OUTLINED IN A COMBINATION OF GLAMP/HREF GUIDANCE
BETWEEN 03-10Z SATURDAY. LOW CONFIDENCE ON CEILINGS SCATTERING
OUT AFTER SUNRISE, SO HAVE WENT AGAINST GUIDANCE AND KEPT LOWER
CEILINGS GIVEN NO PRONOUNCED DRIER AIR/STRONGER WINDS TO HELP
MIX OUT CEILINGS.
OUTLOOK...
SUN...VFR/NO SIG WX.
MON...RAIN AND SNOW SHOWERS DEVELOPING IN THE AFTERNOON NW.
TUE...RAIN AND SNOW SHOWERS CONTINUE AND BECOME AREA WIDE.
WED...VFR/NO SIG WX.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD/DANGELO
SHORT TERM...FITZGERALD/BANGHOFF
LONG TERM...NPB
AVIATION...NPB
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