144
FXUS61 KCTP 301636
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1236 PM EDT MON JUN 30 2025
SYNOPSIS
* STORMY PATTERN RESUMES TODAY AND TOMORROW AS A WARM FRONT,
THEN COLD FRONT PUSHES THROUGH THE REGION, BRINGING A RENEWED
RISK OF STRONG TO SEVERE STORMS AND LOCALLY HEAVY DOWNPOURS
* DRIER/LESS HUMID/MORE COMFORTABLE CONDITIONS ARE LIKELY FROM
MID TO LATE WEEK WITH HIGH CONFIDENCE OF NICE WEATHER ON
INDEPENDENCE DAY
NEAR TERM /UNTIL 10 PM THIS EVENING/
HEALTHY MOISTURE RETURN WILL OCCUR THROUGH THIS AFTERNOON WITH
PWAT VALUES CLIMBING BY ANOTHER 3-4 TENTHS BETWEEN 17-23Z TODAY,
PEAKING FROM ABOUT 1.8 INCHES ACROSS THE NE MTN ZONES TO AROUND
2.25 INCHES ACROSS THE LOWER SUSQ VALLEY.
LOWEST FFG VALUES AND HIGHEST CONCENTRATION OF 3 HOUR QPF ENS
PROBABILITY MATCHED MEAN VALUES OVER 1.5 INCHES GAVE US THE
BACKING TO COLLABORATE/ISSUE A FLASH FLOOD WATCH FOR OUR NW MTNS
AND LAUREL HIGHLANDS THROUGH 10 PM THIS EVENING.
HEAVY SHOWERS AND TSRA FORMING NEAR AND TO THE SOUTH OF A SLOW
MOVING WARM FRONT WILL HAVE THE POTENTIAL TO TRAIN NE ACROSS THE
SAME LOCATIONS AND BRING THE RISK OF FLASH FLOODING.
PERTINENT AND STILL VALID PARTS OF THE PREVIOUS DISCUSSION
FOLLOW -
THIS INFLUX OF MOISTURE WILL OCCUR DOWNSTREAM OF AN
AMPLIFYING MID-UPPER TROUGH MOVING INTO THE UPPER MIDWEST AND
WESTERN GREAT LAKES. NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED BEGINNING EARLY THIS AFTERNOON AND LASTING THROUGH THIS
EVENING AS SHORTWAVE ENERGY SUPPLIES LARGE SCALE FORCING FOR
ASCENT. GIVEN THE PRESENCE OF WEAK/MODEST VERTICAL WIND SHEAR, A
FEW OF THE STORMS COULD BECOME STRONG TO LOCALLY SEVERE. STRONG
BOUNDARY-LAYER HEATING IS EXPECTED WITH 2000+ J/KG OF TALL/THIN
SBCAPE) AMID RELATIVELY WEAK EFFECTIVE SHEAR VALUES OF 25-30
KNOTS. THIS ENVIRONMENT WILL SUPPORT THE POTENTIAL FOR WET
DOWNBURSTS AND DAMAGING WIND GUSTS.
MAX TEMPS WILL RANGE FROM THE LOW-MID 80S ACROSS THE HIGH
TERRAIN OF THE NORTH AND WEST, TO THE UPPER 80S IN THE CENTRAL
AND SOUTHERN VALLEYS.
SHORT TERM /10 PM THIS EVENING THROUGH TUESDAY NIGHT/
STORMS WILL CONTINUE INTO THIS EVENING WITH COLD POOLS TAKING
OVER AND BRINGING AN END TO THE WIDESPREAD SHOWER ACTIVITY AFTER
DARK. GIVEN THE REFUEL OF SURFACE WATER FROM MONDAY'S RAIN AND
SULTRY CONDITIONS TONIGHT, EXPECT FOG TONIGHT INTO TUESDAY
MORNING, ESPECIALLY WHERE LOW CLOUDS CAN BREAK.
THE AFOREMENTIONED MID-LEVEL TROUGH WILL SHIFT EAST FROM THE
GREAT LAKES TO THE NORTHEAST ON TUESDAY. MODERATE MID-LEVEL FLOW
WILL OVERSPREAD MUCH OF THE REGION, INCLUDING PLACING CENTRAL PA
IN THE RIGHT ENTRANCE REGION OF AN UPPER-LEVEL JET. AT THE
SURFACE, A COOL FRONT WILL MOVE EAST ACROSS PA AND WILL BE THE
PRIMARY FOCUS FOR SEVERE THUNDERSTORM POTENTIAL TUESDAY
AFTERNOON/EVENING.
STRONGER SHEAR PROFILES WILL BE PRESENT ON TUESDAY AND THIS MAY
RESULT IN GREATER STORM ORGANIZATION/INTENSITY INCLUDING THE
POTENTIAL FOR A FEW SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WIND GUSTS. STORMS SHOULD EVENTUALLY CONGEAL INTO A
MORE SOLID LINE AS THE FRONT MAKES CLOSER APPROACH, MAINTAINING
A DAMAGING WIND THREAT INTO THE LOWER SUSQUEHANNA VALLEY.
DRIER AIR WILL BEGIN ADVECTING INTO CENTRAL PA LATE TUESDAY INTO
TUESDAY NIGHT WITH DEWPOINTS DROPPING WELL INTO THE 60S.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
* EXPECT A DRIER AND MORE COMFORTABLE STRETCH OF WEATHER FOR
WED-SAT.
* INCREASING CONFIDENCE IN NICE/DRY WEATHER ON JULY 4TH.
THERE IS GROWING CONFIDENCE IN A DRIER AND MORE COMFORTABLE
STRETCH OF WEATHER FROM MIDWEEK INTO THE FIRST WEEKEND OF JULY.
EXPANDING ON THE DRIER/COMFORTABLE STRETCH, WE ARE TALKING
SPECIFICALLY ABOUT: 1) LITTLE TO NO RAINFALL AND 2) NOTICEABLY
LOWER HEAT AND HUMIDITY.
A MOISTURE-STARVED COLD FRONT WILL PROVIDE THE "BEST" CHANCE OF
RAIN THURSDAY PM, BUT OVERALL WE EXPECT THE MAJORITY OF THE
TIME TO BE DRY DURING THE WED-SAT PERIOD.
MAX/MIN TEMPS WILL BE CLOSE TO THE HISTORICAL AVERAGE DURING
THE FIRST WEEK OF JULY. THERE ARE SIGNALS FOR HEAT AND HUMIDITY
TO RAMP UPWARD BY THE END OF THE WEEKEND.
AVIATION /18Z MONDAY THROUGH SATURDAY/
HIGH RES ENSEMBLE GUIDANCE AND INDIVIDUAL CAM MEMBERS SHOW
CONVECTIVE SHOWERS AND TSRA STEADILY EXPANDING IN COVERAGE FROM
SW TO NE ACROSS CENTRAL PA AND THE SUSQ VALLEY DURING THE MID
AFTERNOON THROUGH EARLY EVENING HOURS.
THE BULK OF THE TIME (95+% OF THE TAF PERIOD) WILL STAY VFR, BUT
BRIEF PERIODS OF MVFR ARE LIKELY WITH HEAVY SHOWERS OR TSRA
AT MOST AIRFIELDS BETWEEN 20Z TODAY AND 00-01Z TUESDAY
PREDOMINANTLY VFR CONDS ARE EXPECTED TO CONTINUE OVERNIGHT,
ALTHOUGH THERE IS LOW CONFIDENCE THAT SOME SPOTS COULD SEE THE
DEVELOPMENT OF FOG/LOW CLOUDS DURING THE PREDAWN HOURS. HIGH AND
MID LEVEL CLOUDS MAY HELP TO LIMIT FOG DEVELOPMENT.
OUTLOOK...
TUE...PM SHOWERS & T-STORMS LIKELY; AREAS OF FOG & LOW CLOUDS
AS WELL.
WED...AM FOG, THEN VFR.
THU...PRIMARILY VFR; STRAY PM SHOWER/T-STORM POSSIBLE.
FRI...AM FOG POSSIBLE; OTHERWISE VFR.
CTP WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR PAZ004-005-010-
017-024-033.
SYNOPSIS...GUSEMAN/LAMBERT
NEAR TERM...GUSEMAN/LAMBERT
SHORT TERM...GUSEMAN/STEINBUGL
LONG TERM...STEINBUGL/EVANEGO
AVIATION...LAMBERT/MARTIN
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