363
FXUS61 KPBZ 291700
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
100 PM EDT TUE SEP 29 2026
WHAT HAS CHANGED
UPCOMING WEEKEND PRECIPITATION CHANCES HAVE DECREASED, OTHERWISE
NO MAJOR CHANGES WERE MADE TO THE LATEST FORECAST.
KEY MESSAGES
1) MAINLY DRY THROUGH THURSDAY, BEFORE SHOWER CHANCES RETURN
WITH A FRIDAY COLD FRONT
2) COOLER WITH PERIODIC SHOWER CHANCES FOR THE UPCOMING WEEKEND
DISCUSSION
KEY MESSAGE 1...
A RIDGE OF HIGH PRESSURE IS EXPECTED TO MAINTAIN DRY WEATHER FOR
MUCH OF THE AREA THROUGH THURSDAY. THE EXCEPTION IS WEDNESDAY
NIGHT, WHERE A WEAK CROSSING SHORTWAVE AND WARM ADVECTION COULD
RESULT IN A FEW SHOWERS NORTH OF PITTSBURGH. THE RIDGE SHOULD
STRENGTHEN AGAIN ON THURSDAY AHEAD OF AN APPROACHING TROUGH,
WITH DRY WEATHER RETURNING. THURSDAY WILL LIKELY BE THE WARMEST
DAY OF THE WEEK, WITH HIGHS AROUND 80 OUTSIDE OF THE HIGHER
TERRAIN.
A SHORTWAVE TROUGH, AND AN ASSOCIATED SURFACE COLD FRONT, IS
EXPECTED TO ADVANCE EASTWARD FROM THE MIDWEST ON THURSDAY,
APPROACHING AND CROSSING THE UPPER OHIO VALLEY REGION ON FRIDAY.
THE UPPER TROUGH IS PROGGED TO WEAKEN AS IT MOVES EASTWARD
ACROSS OUR REGION ON FRIDAY. INCREASING FLOW ALOFT WILL RESULT
IN INCREASING SHEAR DURING THE DAY, WITH THE AREA UNDER THE
RIGHT ENTRANCE REGION TO AN UPPER LEVEL JET. INSTABILITY IS
PROGGED TO REMAIN MINIMAL AT THIS TIME, WITH SB CAPE AROUND 250
J/KG OR LESS, MAINLY SOUTH OF PIT. ML GUIDANCE INDICATES LITTLE
POTENTIAL FOR SEVERE STORMS AS WELL. THE MOST FAVORABLE TIMING
FOR FROPA IS EARLY AFTERNOON NORTH OF PIT, WITH MID TO LATE
AFTERNOON FOR POINTS SOUTHWARD. AT THIS TIME, PROBABILITIES FOR
AT LEAST A QUARTER OF AN INCH OF RAIN RANGE FROM 60 TO 80
PERCENT, THOUGH ARE LESS THAN 50 PERCENT FOR A HALF AN INCH.
KEY MESSAGE 2...
BROAD UPPER TROUGHING IS PROGGED TO SET UP ACROSS THE NE CONUS
THROUGH THE UPCOMING WEEKEND. SATURDAY SHOULD BE MAINLY DRY AND
COOLER AS SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTH, THOUGH
A CROSSING SOUTHERN STREAM WAVE SHOULD RESULT IN SHOWER CHANCES
MAINLY SOUTH OF I-70. SHOWER CHANCES THEN INCREASE ON SUNDAY AS
A NORTHERN STREAM SHORTWAVE ROTATES THROUGH THE BROAD UPPER
TROUGH. COOLER TEMPERATURES ARE EXPECTED, WITH HIGHS JUST BELOW
SEASONABLE LEVELS.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
REMAINING MVFR STRATOCU CIGS EAST OF AN LBE TO MGW LINE SHOULD
GRADUALLY IMPROVE TO VFR WITH MIXING THROUGH MID AFTERNOON.
ELSEWHERE, AS THE STRATOCU CLEARS AND SURFACE HEATING OCCURS,
EXPECT ADDITIONAL DIURNAL CU DEVELOPMENT THROUGH LATE AFTERNOON.
THE LOWER CLOUDS SHOULD SCATTER OUT AND DISSIPATE TONIGHT AS
HIGH PRESSURE MOVES OVERHEAD, THOUGH SOME PATCHY FOG AND STRATUS
WILL BE POSSIBLE, ESPECIALLY WHERE CLOUDS LINGER THIS AFTERNOON,
LIMITING MIXING DOWN OF DRIER AIR.
ANY FOR OR STRATUS SHOULD DISSIPATE WEDNESDAY MORNING WITH
MIXING, WITH INCREASING HIGH CLOUDS IN WARM ADVECTION, AND A
FEW DIURNAL CUMULUS THROUGH THE REST OF THE DAY.
OUTLOOK...
VFR IS EXPECTED THROUGH THURSDAY, THOUGH A FEW SHOWERS ARE
POSSIBLE N OF PIT WEDNESDAY NIGHT WITH A CROSSING DISTURBANCE.
RESTRICTIONS IN SHOWERS ARE LIKELY WITH A FRIDAY COLD FRONT.
RESTRICTIONS ARE POSSIBLE SOUTH OF I-70 SATURDAY, AND ACROSS THE
REMAINDER OF THE ARE SUNDAY, WITH CROSSING DISTURBANCES.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...WM
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