833
FXUS61 KCTP 040928
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
528 AM EDT SUN MAY 4 2025
SYNOPSIS
* PERIODS OF RAIN THIS MORNING WILL TRANSITION INTO AREAS OF
SHOWERS WITH ISOLATED TO SCATTERED STRONG, TO POSSIBLY SEVERE
THUNDERSTORMS THIS AFTERNOON AND EARLY THIS EVENING.
* MONDAY AND TUESDAY WILL FEATURE MULTIPLE ADDITIONAL BANDS OF
MODERATE TO HEAVY RAINFALL FROM SHOWERS AND SCATTERED
AFTERNOON THUNDERSTORMS MOVING NORTH TO NORTHWEST ACROSS THE
COMMONWEALTH. THE BULK OF THIS RAIN WILL BE LARGELY
BENEFICIAL, BUT SOME MINOR FLOODING WILL BE POSSIBLE WITH ANY
REPEATED ROUNDS OF HEAVY RAIN.
* BECOMING DRIER LATE IN THE UPCOMING WEEK WITH A TREND TOWARD
BELOW NORMAL TEMPERATURES.
NEAR TERM /UNTIL 6 PM THIS EVENING/
A LARGE AREAS OF LIGHT TO BRIEFLY MODERATE RAIN WAS ADVANCING
SLOWLY NORTHEAST ACROSS THE STATE EARLY TODAY, WITH NO THUNDER
NOTED. A SECOND MID/UPPER LEVEL VORT LOBE AND ASSOCIATED NW/SE
ELONGATED AREA OF RAIN AND A FEW TSRA WAS LIFTING NORTH FROM
CENTRAL VA AND WVA AND WILL MOVE INTO SOUTHERN PA (AND
SPECIFICALLY THE LOWER SUSQ VALLEY LATE THIS MORNING AND EARLY
THIS AFTERNOON.
WIDESPREAD MULTI-LAYERED BKN-OVC CLOUD COVER TODAY WILL BREAK A
BIT FOR A FEW TO SEVERAL HOURS DURING THE AFTERNOON ACROSS SCENT
AND SW PA ALLOW FOR MU CAPE VALUES TO CLIMB TO BETWEEN 1000-1500
J/KG. THE NOSE OF A MID LEVEL JET IMPINGING ON THAT PART OF OUR
CWA WILL COMBINE WITH SLIGHTLY STRENGTHENING LOW LEVEL SOUTHERLY
FLOW TO PROVIDE AMPLE SHEAR FOR SOME DISCRETE, ORGANIZED
UPDRAFTS WITH ISOLATED TO SCATTERED STRONG/SEVERE TSRA. SPC'S DY
1 MRGL RISK FOR SVR ENCOMPASSES THIS PART OF THE CWA AND WPC'S
MRGL EXCESSIVE RAIN AREA COVERS PRACTICALLY THE ENTIRE CWA
TODAY.
ALTHOUGH THE RAINFALL OVER THE PAST FEW DAYS HAS BEEN HIGHLY
BENEFICIAL, FFG HAS DIPPED SOMEWHAT AND THE NWD/NNWD TRAINING
OF INDIVIDUAL HEAVY SHRA/TSRA COULD PRESENT SOME LOCALIZED
SIGNIFICANT RISES OR MINOR FLOODING OF A FEW SMALL STREAMS.
LOOK FOR HIGH TEMPS TODAY TO VARY FROM THE UPPER 50S/LOW 60S
ACROSS THE NORTHERN TIER OF PA TO THE UPPER 60S AND LOW/MID 70S
IN THE SOUTH - DEPENDING ON ELEVATION.
SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/
A BLOCKING PATTERN WILL REMAIN OVER THE FCST AREA TONIGHT
INTO THE NEW WEEK WITH A DEEP/VERTICALLY STACKED LOW IN THE OH
VALLEY. SOUTHERLY FLOW ON THE EAST SIDE OF THE LOW WILL CHANNEL
MOISTURE INTO THE AREA WITH PERIODS OF RAIN AND AFTERNOON STORMS
EXPECTED MONDAY AND TUESDAY.
A FEW STRONGER STORMS ARE POSSIBLE OVER ANY PORTION OF THE CWA
MONDAY AFTERNOON THANKS TO THE COMBINATION OF MARGINAL
INSTABILITY, SUFFICIENT SHEAR, AND GRADUALLY COOLING ALOFT WITH
STEEPENING MID-LEVEL LAPSE RATES. THE THREAT FOR SEVERE WEATHER
APPEARS TO DECREASE INTO TUESDAY AND WEDNESDAY AS THE SLOW
MOVING UPPER LOW GRADUALLY FILLS.
WHILE RAINFALL WILL BE CERTAINLY BENEFICIAL AND BRING
SOME RELIEF TO DROUGHT CONDITIONS PARTICULARLY IN THE SOUTHEAST
PART OF THE FORECAST AREA, WE WILL NEED TO CONTINUE CLOSELY
MONITORING FOR POTENTIAL TARGET AREAS WHERE REPEATED ROUNDS OF
HEAVY RAINFALL COULD PRODUCE LOCALLY HEAVY 1-3 HOUR TOTALS AND
MAY RESULT IN LOCALIZED FLOODING IN URBAN AND POOR DRAINAGE
AREAS.
WPC HAS MAINTAINED MARGINAL EXCESSIVE RAIN RISKS FOR MONDAY AND
TUESDAY WITH A GRADUAL EASTWARD SHIFT OF THOSE AREAS COINCIDENT
WITH A SLOWLY ADVANCING UPPER LOW. SHOWER ACTIVITY SHOULD TREND
MORE STRATIFORM IN NATURE (AS OPPOSED TO CONVECTIVE) AS WE GET
INTO THE UPCOMING WEEK, WHICH WILL LIMIT THE RISK OF HEAVY
RAINFALL SOMEWHAT, BUT A SLIGHT RISK UPGRADE AT SOME POINT WOULD
NOT BE TOO SURPRISING. ENSEMBLE MEANS PAINT A WIDESPREAD 2-3"
ACROSS THE REGION THROUGH TUESDAY, WITH LOCALLY HIGHER AMOUNTS
IN THUNDERSTORMS.
THIS PERIOD WILL REMAIN MILD RELATIVE VS. CLIMO WITH THE
LARGEST DEPARTURES FROM NORMAL IN THE OVERNIGHT MIN TEMPS
ON THE ORDER OF +10-20F ABOVE THE HISTORICAL AVERAGE. NOT MUCH
IN THE WAY OF SUNSHINE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
THE UNSETTLED PATTERN CONTINUES INTO THE LONG-TERM THROUGHOUT
THE MIDDLE OF WEEK AS A CLOSED LOW MOVES NORTHEAST OF THE AREA.
THE BULK OF HEAVIEST RAINFALL WILL GRADUALLY BEGIN LIFTING
NORTHEAST OF THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT;
HOWEVER, LOCALIZED MAXIMA ACROSS PORTIONS OF THE ENDLESS
MOUNTAINS WILL RETAIN SOME THREAT FOR URBAN AND POOR DRAINAGE
FLOODING ACROSS THE NORTHEASTERN SECTOR OF THE CWA. HIGHER
CONFIDENCE REMAINS IN THIS SOLUTION WITH MODEL DETERMINISTIC
GUIDANCE OUTLINING FAVORABLE AGREEMENT.
PROGRESSING INTO THE END OF THE WEEK, MODEL GUIDANCE HAS
STARTED TO HONE IN ON DRIER CONDITIONS PREVAILING BY LATE
THURSDAY AND INTO FRIDAY; HOWEVER, WOULD REALISTICALLY LIKE TO
SEE ANOTHER CYCLE OF DRY CONDITIONS PREVAILING ACROSS THE CWA
BEFORE NIXING MENTIONS AT THIS TIME. GIVEN THERE IS SOME (ALBEIT
SHRINKING) UNCERTAINTY, HAVE DECIDED TO ROLL WITH NBM
THROUGHOUT MUCH OF THE LATE WEEK PERIOD. LONG RANGE ENSEMBLES
PROG HIGH PRESSURE BUILDING IN BY EARLY FRIDAY MORNING, LEADING
THE SIGNAL FOR DRYER CONDITIONS LEADING INTO NEXT WEEKEND.
AVIATION /09Z SUNDAY THROUGH THURSDAY/
06Z TAFS SENT.
INTERESTING WEAKNESS IN RADAR RETURNS NEAR INTERSTATE 99, GIVEN
THE TERRAIN, AND A LOW LEVEL LAYER OF COOLER AIR. THIS AREA,
WHICH INCLUDES AOO, UNV, AND AT THE CURRENT TIME, JST, LOOKING
AT FAIRLY GOOD CONDITIONS. THUS MAIN CHANGE FROM EARLIER
FORECAST, WENT WITH BETTER CONDITIONS THAN GUIDANCE WOULD
INDICATE.
CLUSTER OF HEAVIER RAIN LIFTING NORTHWARD MAY CLIP MDT,
BUT LOOKS LIKE IT WILL STAY WEST OF LNS. COULD BE AN ISOLATED
RUMBLE OF THUNDER IN THAT CLUSTER, BUT ECHO TOPS LOW FOR
THUNDER, SO LEFT THUNDER OUT.
CONDITIONS WILL LIKELY DROP AFTER SUNSET THIS SUNDAY EVENING.
OVERALL NOT MUCH CHANGE IN THE OVERALL PATTERN EXPECTED BEFORE
MID WEEK.
OUTLOOK...
MON-TUE...FREQUENT RAIN SHOWERS; SOME LOCALLY HEAVY WITH
PROLONGED SUB-VFR CONDITIONS.
WED-THU...SHOWERS BECOME MORE SCATTERED WITH HIGHER CHANCES IN
THE AFTERNOON/EVENING HOURS. RESTRICTIONS POSSIBLE.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/BANGHOFF
LONG TERM...NPB/BOWEN
AVIATION...MARTIN
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