263
FXUS61 KCTP 010055
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
855 PM EDT TUE MAR 31 2026
WHAT HAS CHANGED
* REFINED TIMING OF STORMS ACROSS THE N
* LOWERED TEMPS A LITTLE ON WED AND SIGNIFICANTLY ON THURS
(MAINLY IN THE EAST)
KEY MESSAGES
1) STORMS LATE TODAY AND TONIGHT WILL CAUSE LOCALIZED HEAVY
RAIN AND LIKELY CAUSE STRONG, DAMAGING WINDS AND MAYBE LARGE
HAIL AND AN ISOLATED TORNADO.
2) SLOW MOVING FRONT WILL MOVE DOWN FROM THE NORTH TONIGHT AND WAGGLE
NORTH/SOUTH OVER THE CWA FOR THE NEXT SEVERAL DAYS.
DISCUSSION
KEY MESSAGE 1: STORMS LATE TODAY AND TONIGHT WILL CAUSE
LOCALIZED HEAVY RAIN AND LIKELY CAUSE STRONG, DAMAGING WINDS AND
MAYBE LARGE HAIL AND AN ISOLATED TORNADO.
WATCH #79 HAS JUST BEEN ISSUED UNTIL 9 PM. WHILE CLOUD COVER AND
STABILIZATION FROM EARLIER SHOWERS/STORMS IS AROUND AT THIS TIME
(18Z), SOME DESTABILIZATION IS EXPECTED BEFORE FORCING ARRIVES
FROM THE W. LINE OF LIGHT SHOWERS OVER CLE IS LIKELY ALONG A
WEAK TROUGH AND IS ATTACHED TO A PARTICULARLY ENERGETIC STORM
OVER LE HEADED FOR BUF. WE WERE OK WITH ADDING THE NORTHERN TIER
OF COUNTIES INTO THE WATCH WITH AN EYE TO THAT LINE HAVING SOME
HOPE OF DEVELOPING. IN FACT, A FEW CGS JUST SHOWED UP N OF
ASHTABULA CO OH. SO, IT'S ON TRACK, JUST MORE LIKELY FOR NY THAN
OUR CWA. WE STILL FEEL THE MAIN EVENT FOR CENTRAL PA WILL BE A
LITTLE LATER IN THE DAY (PERHAPS NOT UNTIL 5 OR 6 PM ONWARD).
SO, THE WATCH RUNNING UNTIL 9 PM IS A GOOD START. IF STORMS LOOK
LIKE THEY WILL SNEAK TO THE SOUTH A BIT MORE BEFORE THAT TIME,
WE COULD CERTAINLY EXPAND THE WATCH SOUTHWARD. WE WILL PROBABLY
NEED A SECOND WATCH FOR LATER THIS EVENING AS WE EXPECT THE BEST
FORCING TO ARRIVE LATE IN THE DAY. STORM THREATS OF ALL THREE
FLAVORS (WIND, HAIL, AND TORNADO) STILL LOOK POSSIBLE, BUT WIND
DAMAGE IS THE MAIN WORRY. THE SHEAR ALONG ANY DIFFERENTIAL
HEATING BOUNDARIES OR OUTFLOW BOUNDARIES (LIKE THE ONE THE BIG
LE CELL MAY CREATE) WILL BE HIGH, SO THE TORNADO THREAT IS STILL
NON-ZERO. DEEP LAYER SHEAR OF 50+KT AND 100MB MIXED-LAYER CAPE
OF 800-100J/KG IN ADVANCE OF THAT PRE-FRONTAL TROUGH ARE CUT OFF
FOR THE MOMENT BY CIN OF SOME REPUTE. OVERALL, THE STORM
THREATS DO LOOK MORE LIKELY AFTER 5 PM, BUT WE'LL GET THE WORD
OUT EARLY TODAY.
HEAVY RAIN IS ALSO A POTENTIAL TROUBLE FOR THE NRN TIER. EARLIER
RAIN/STORMS THAT DIPPED SOUTH TO NEAR I-80 MADE LIGHT RAINFALL,
BUT EVERY LITTLE BIT CAN ADD UP WHEN MULTIPLE STORMS ARE
EXPECTED TO AFFECT THE AREA THIS EVENING/TONIGHT. NOT STRONG
ENOUGH REASONS FOR A FLOOD WATCH AT THIS POINT, THOUGH, AS THE
FFG IS STILL IN THE .
---------------------------
KEY MESSAGE 2: SLOW MOVING FRONT WILL MOVE DOWN FROM THE NORTH
TONIGHT AND WAGGLE NORTH/SOUTH OVER THE CWA FOR THE NEXT SEVERAL
DAYS.
THE FRONT OVER ONT WILL DROP SOUTHWARD INTO PA TONIGHT, BUT NOT
GET TOO FAR INTO THE CWA BEFORE SUNRISE. PLENTY OF CLOUDS AND
SCATTERED TO NUMEROUS SHOWERS WILL STILL BE AROUND IN THE
MORNING. THESE SHOULD GET MORE NUMEROUS THROUGHOUT THE DAY, AND
THERE IS A MRGL RISK OF SEVERE WX (WIND/HAIL) ACROSS THE SRN
HALF OF THE CWA. THE CLOUDS AND STABLE CONDITIONS IN THE AM WILL
POSE A CHALLENGE FOR STORMS TO GROW BIG. BUT, THERE WILL LIKELY
BE SOME BREAKS IN THE CLOUDS LATE IN THE AM AND EARLY AFTN TO
GET SOME DESTABILIZATION GOING. HAVE NUDGED GUIDANCE TEMPS DOWN
A BIT FOR WED -- AND EVEN MORE-SO ON THURSDAY, ESPECIALLY IN
THE EASTERN HALF OF THE CWA. DEEP EASTERLY FLOW AND CLOUD COVER
WILL MAKE IT A CHALLENGE TO GET TEMPS OUT OF THE 40S OVER
EASTERN PA, AND ABOVE 55F IN THE EASTERN HALF OF OUR CWA. JST
AND BFD WILL BE LAUGHING AT US AS THEY TOP OUT IN THE 60S AND
PERHAPS L70S - WHERE THE FRONT PUSHES NORTH AS A WARM FRONT.
THEY WILL HAVE HIGHER POPS THAN THE EAST AS THE FRONT SHOULD
HELP TOUCH OFF SCT/NMRS SHRA/TSRA.
THE FRONT LIFTS NORTH/EASTWARD THROUGH THE REST OF THE CWA
THURSDAY NIGHT OR FRIDAY MORNING. WE WILL STILL CARRY POPS THRU
THE DAY FRI AS MANY GUIDANCE MODELS SHOW THE FRONT RETURNING AS
A COLD FRONT INTO THE W. A TRAIN OF SFC LOWS WILL CARRY MOISTURE
INTO THE AREA THROUGH THE WEEKEND. A GOOD PUSH OF COLDER AIR
FINALLY BUSTS THROUGH LATE SUN OR SUN NIGHT. IT LOOKS LIKE IT
WILL BE COLD ENOUGH TO MAKE SOME SNOW MIX IN FOR THE HIGHER
ELEVATIONS OF THE NW IN LAST COULD OF HOURS. A STRAY SHSN IS NOT
OUT OF THE QUESTION MONDAY IN THE FAR NW, TOO. BUT, WE'LL LEAVE
POPS UNMENTIONABLE AT THIS RANGE.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
SCATTERED THUNDERSTORMS ARE CURRENTLY ENTERING OUR NORTHWESTERN
COUNTIES, WITH KBFD BRIEFLY REPORTING +TSRA AND GUSTS TO 42 KTS
AS A LINE OF THUNDERSTORMS MOVED THROUGH. SCATTERED SHOWERS AND
THUNDERSTORMS WILL TREND SOUTHEASTWARD THIS EVENING AHEAD OF A
SLOW-MOVING COLD FRONT, WITH STORMS WEAKENING AS THEY MOVE
TOWARD SOUTH-CENTRAL PA AS INSTABILITY DECREASES OVERNIGHT.
PROB30 GROUPS FOR -TSRA WERE INCLUDED FOR KIPT AND KUNV BETWEEN
03Z-08Z WHERE MUCAPE VALUES REMAIN SUFFICIENT TO SUPPORT
LIGHTNING (100-250 J/KG ON THE HREF), WITH LOWER CONFIDENCE IN
THUNDERSTORMS PRECLUDING PROB30S AT KMDT AND KLNS.
MOREOVER, AS SURFACE WINDS DIMINISH THIS EVENING, LLWS WILL
BECOME A CONCERN AS A 40-55 KT LLJ DEVELOPS OVER CENTRAL PA.
THIS LLJ WILL WEAKEN WEDNESDAY MORNING AS DAYTIME HEATING
PROMOTES BOUNDARY LAYER MIXING.
CEILINGS AND VISIBILITIES WILL LOWER FROM NORTH TO SOUTH
THROUGH 00Z THURSDAY AS THE COLD FRONT SLOWLY MOVES SOUTHWARD
ACROSS THE REGION, WITH THE FRONT REACHING THE NORTHERN TIER
AROUND 08Z WEDNESDAY, THEN TO THE LOWER SUSQUEHANNA VALLEY BY
00Z THURSDAY. HIGHEST CONFIDENCE IN MVFR FOR THE TAF PERIOD IS
AT KJST DUE TO UPSLOPE WESTERLY WINDS AND OROGRAPHIC LIFT, AND
AT KBFD WHERE COOL/MOIST AIR WILL BE FURTHER ENTRENCHED BEHIND
THE COLD FRONT. LAMP GUIDANCE ALSO HIGHLIGHTS IFR BEING POSSIBLE
AT KBFD AFTER 09Z (50% CHANCE), PARTICULARLY BETWEEN 11Z AND
14Z WHERE PROBABILITIES RISE TO 60-70% FOR IFR, CORRESPONDING TO
THE DIURNAL MINIMUM. ON THE OTHER HAND, KMDT AND KLNS ARE
EXPECTED TO REMAIN IN THE WARM SECTOR FOR MUCH OF TOMORROW,
STAYING VFR THROUGH MUCH OF THE PERIOD. WITH THAT SAID, THE LAMP
SUGGESTS AN INCREASING CHANCE (30-40%) FOR MVFR AT THESE
SOUTHERN SITES BY 22Z WEDNESDAY WHEN THE COLD FRONT MAY PASS
THROUGH. WINDS WILL SHIFT FROM WEST-SOUTHWEST TO NORTH AS THE
FRONT PASSES OVER AIR SITES IN THE REGION, WITH SUSTAINED WINDS
GENERALLY BETWEEN 10-15 KTS.
IN TERMS OF PRECIPITATION TOMORROW, SCATTERED SHOWERS ARE
EXPECTED TO CONTINUE ACROSS THE COMMONWEALTH, WITH THE FOCUS FOR
RENEWED CONVECTION OVER THE LOWER SUSQUEHANNA VALLEY
(KMDT/KLNS) PRIMARILY AFTER 18Z. THE HREF SHOWS SBCAPE VALUES OF
500-1000 J/KG WITHIN THAT AREA, WHICH WOULD BE SUFFICIENT FOR
THUNDERSTORMS, THOUGH COVERAGE AND TIMING UNCERTAINTIES PRECLUDE
FURTHER DETAILS IN THE TAF.
OUTLOOK...
WED-SAT...NUMEROUS SHRA WITH RESTRICTIONS POSSIBLE, ESPECIALLY
ON THE COOL SIDE OF A FRONTAL BOUNDARY THAT OSCILLATES ACROSS
CENTRAL PA DURING THIS TIMEFRAME.
SUN...RESTRICTIONS POSSIBLE WITH SHOWERS AND THUNDERSTORMS AHEAD
OF A STRONG COLD FRONT.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...DANGELO
KEY MESSAGES...DANGELO
DISCUSSION...DANGELO/COLBERT/BAUCO
AVIATION...TEARE
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