740
FXUS61 KPBZ 041952
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
352 PM EDT THU SEP 4 2025
SYNOPSIS
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TODAY WITH A
PASSING COLD FRONT. FOG EXPECTED OVERNIGHT. A SECOND COLD FRONT
MAY RETURN ISOLATED THUNDERSTORM LATE TOMORROW EVENING. COOLER
CONDITIONS ARE EXPECTED OVER THE WEEKEND.
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
KEY MESSAGES:
- SHOWERS AND LOCALIZED THUNDERSTORMS THIS AFTERNOON/EVENING
- GUSTY CONDITIONS MAY OCCUR WITH SHOWERS/STORMS
- FOG EXPECTED TONIGHT
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A COLD FRONT IS CURRENTLY SITUATED BETWEEN PITTSBURGH AND
CLEVELAND THIS AFTERNOON. WITH PRE-FRONTAL SHOWERS THIS MORNING
AND HEAVY CLOUD COVERAGE, THE ENVIRONMENT IS CURRENTLY
UNFAVORABLE FOR STRONG TO SEVERE STORMS FOR A LARGE PORTION OF
OUR AREA. IF AN ISOLATED STORM DOES DEVELOP, IT WOULD LIKELY BE
SOUTHEAST OF PITTSBURGH OR NEAR THE LAUREL HIGHLANDS IN THE NEXT
4 HOURS.
AFTER DARK, PROBABILITY OF THUNDERSTORMS RAPIDLY DECREASES WITH
THE LOSS OF SURFACE HEATING AND THE FRONT STALLING NEAR THE
RIDGES.
AFTER MIDNIGHT, THE POTENTIAL FOR DENSE FOG INCREASES WITH LIGHT
WINDS AT THE SURFACE AND BOUNDARY LAYER SATURATION. THE MOST
LIKELY AREAS THAT WILL BE IMPACTED BY FOG WILL BE NORTH OF
PITTSBURGH AND IN THE VICINITY OF THE STATIONARY FRONT.
SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/
KEY MESSAGES:
- THE PASSAGE OF A SECONDARY COLD FRONT WILL INCREASE THE
POTENTIAL FOR STRONG TO SEVERE STORMS FRIDAY EVENING INTO
EARLY SATURDAY MORNING
- RAIN CHANCES CONTINUE INTO SATURDAY AFTERNOON; NEAR RECORD
LOW MAXIMUM TEMPERATURE
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THE UPPER LEVEL PATTERN WILL EXPERIENCE A QUICK PIVOT BACK TO
SOUTHWESTERLY FLOW AHEAD OF THE NEXT DEEP SHORTWAVE ROUNDING
THROUGH THE BROADER GREAT LAKES TROUGH. MODEST WARM ADVECTION
AND INITIALLY SUNNIER SKIES ARE LIKELY TO AID TEMPERATURE
RETURNING NEAR THE DAILY AVERAGE HIGH. SUBSIDENCE AHEAD OF THE
APPROACHING MID-LEVEL JET ALSO WILL AID IN FRIDAY INITIALLY
STARTING DRY.
BY LATE FRIDAY EVENING, A NEW COLD FRONT IS EXPECTED TO ADVANCE
INTO THE REGION. JOINT PROBABILITIES OF EFFECTIVE SHEAR
(+30KTS) AND INSTABILITY (500J/KG) IS ELEVATED (ABOVE 70%) AND
COULD PROMPT ORGANIZED STORMS DURING THE TIME PERIOD OF OF 4PM
FRIDAY TO 2AM SATURDAY. SEVERE STORMS COULD PRODUCE DAMAGING
WINDS AND PERHAPS AN ISOLATED TORNADO. STORMS CELLS MOVING DUE
EAST WOULD LIKELY INGEST THE BEST ROTATION UPDRAFTS FOR A
TORNADO THREAT.
THE SEVERE THREAT WILL DECREASE BEFORE DAWN ON SATURDAY.
HOWEVER, REMNANT CONVECTION TOWARDS OUR SOUTHWEST IS EXPECTED TO
TRACK THROUGH THE REGION IN WAVES ON SATURDAY.
THE COMBINATION OF EXCESSIVE CLOUD COVER, RAIN, AND NEAR SURFACE
COLD ADVECTION SATURDAY MEANS AREA HIGH TEMPERATURE MAY BE NEAR
RECORD LOW. SITES THAT WOULD BE WITHIN 3-4 DEGREES FROM TYING OR
BREAKING THE RECORD ARE WHEELING (HLG) AND NEW PHILADELPHIA
(PHD).
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGES:
- BELOW AVERAGE TEMPERATURES ARE EXPECTED ON SUNDAY
- A LAKE ENHANCED SHOWER NORTH OF I-80 ARE EXPECTED
- WARMING TREND MONDAY INTO WEDNESDAY
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AS THE AFOREMENTIONED UPPER-LEVEL TROUGH SAGS INTO THE OHIO
RIVER VALLEY SUNDAY, EXPECTED BELOW AVERAGE TEMPERATURES TO
CONTINUE. PREVAILING WESTERLY FLOW OVER THE GREAT LAKES WILL
LIKELY KEEP LAKE ENHANCED SHOWERS NORTH OF I-80.
A GRADUAL WARMING PATTERN IS EXPECTED AS THE UPPER-LEVEL TROUGH
EXITS NORTH AND ZONAL FLOW RETURNS MONDAY INTO TUESDAY.
PROBABILITY OF PRECIPITATION IS CONSIDERED LOW MONDAY INTO
WEDNESDAY WITH BUILDING HIGH PRESSURE TO OUR WEST.
AVIATION /20Z THURSDAY THROUGH TUESDAY/
AREAS OF SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED
THROUGH THE AFTERNOON WITH THE APPROACH AND PASSAGE OF A COLD
FRONT. INSTABILITY HAS BEEN LIMITED WITH CLOUD COVER AND
SHOWERS. LOWERED THE TEMPO FOR THUNDERSTORMS TO PROB30S FOR MOST
AIRPORTS THROUGH THE AFTERNOON. MVFR TO IFR CONDITIONS ARE
EXPECTED WITH REDUCED CIGS AND VSBY AHEAD OF THE FRONT.
IMPROVEMENT TO MAINLY VFR IS EXPECTED AFTER FROPA LATE THIS
AFTERNOON INTO THIS EVENING, BEFORE CONDITIONS DETERIORATE TO
IFR AGAIN OVERNIGHT AS STRATUS AND FOG DEVELOPS WITH LOW LEVEL
MOISTURE IN PLACE. STRATUS SHOULD SCATTER OUT FRIDAY MORNING AS
MIXING BEGINS.
OUTLOOK.
LOW CIGS ARE POSSIBLE INTO FRIDAY MORNING WITH LOW LEVEL
MOISTURE IN PLACE. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE
LIKELY, LATE FRIDAY INTO SATURDAY WITH A CROSSING REINFORCING
COLD FRONT. MAINLY VFR IS THEN EXPECTED THROUGH TUESDAY, THOUGH
A CROSSING UPPER TROUGH AND COLD AIR ALOFT COULD LEAD TO CIG
RESTRICTIONS N OF PIT SUNDAY INTO MONDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...HEFFERAN
NEAR TERM...HEFFERAN
SHORT TERM...HEFFERAN
LONG TERM...HEFFERAN
AVIATION...WM
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