669
FXUS61 KPBZ 081141
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
741 AM EDT FRI AUG 8 2025
SYNOPSIS
AS DRY WEATHER CONTINUES, LOOK FOR AREA TEMPERATURE TO SLOWLY
RISE THROUGH THE WEEKEND AND HOLD AT THE ABOVE NORMAL LEVELS
INTO NEXT WEEK. WIDESPREAD PRECIPITATION CHANCES WILL INCREASE
TUESDAY INTO WEDNESDAY.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- DRY WEATHER WITH SEASONABLE TEMPERATURE CONTINUES
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A PERSISTENCE FORECAST TODAY AS WEAK FLOW ALOFT COMBINED WITH
SURFACE RIDGING STRETCHING INTO NEW ENGLAND FOSTERS SEASONABLE
TEMPERATURE AND DRY WEATHER. SUBTLE INFLUX OF LOW TO MID-LEVEL
MOISTURE WITHIN SE SURFACE FLOW FROM THE ATLANTIC MAY AID
PERIODS OF SCATTERED TO BROKEN CLOUD DECKS FAVORING FAR
SOUTHWEST PA INTO THE WV HIGH TERRAIN, WHICH COULD ACT TO LIMIT
HEATING BY A DEGREE IF IT COVERAGE PERSISTS LONG ENOUGH.
LOSS OF DIURNAL HEATING WILL SEE THE EROSION OF MOST CLOUDS
TONIGHT, RESULTING IN ANOTHER MOSTLY CLEAR NIGHT WITH SEASONABLE
TEMPERATURE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
KEY MESSAGES:
- TEMPERATURE WILL RISE ABOVE NORMAL OVER THE WEEKEND, BUT
LIMITED MOISTURE SHOULD KEEP HEAT INDICES BELOW CRITERIA.
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THERE REMAINS VERY LITTLE CHANGE TO THE WEEKEND OUTLOOK AS A NEW
ENGLAND SURFACE HIGH COMBINED WITH RIDGING ALOFT ENSURE DRY
WEATHER. THE UPPER OHIO RIVER VALLEY WILL EXPERIENCE SLIGHT
HEIGHT RISES ALOFT AS THE RIDGE SHIFTS EAST, WHICH WILL PROMOTE
A GRADUAL RISE IN AREA TEMPERATURE. HIGHS SATURDAY ARE EXPECTED
TO BE AROUND 5 DEGREES ABOVE NORMAL WHILE SUNDAY IS CLOSER TO
10. FORTUNATELY, THE LACK OF MOIST ADVECTION GIVEN WEAK SURFACE
FLOW WILL KEEP DEWPOINTS AT BAY AND LIMIT HEAT INDICES TO THE
UPPER 80S AND LOWER 90S.
LONG TERM /MONDAY THROUGH THURSDAY/
KEY MESSAGES:
- ABOVE-NORMAL TEMPERATURE CONTINUES MONDAY
- RAIN CHANCES INCREASE AREAWIDE TUESDAY AND WEDNESDAY, ALTHOUGH
UNCERTAINTY IN COVERAGE AND TIMING EXISTS
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HIGH CONFIDENCE EXISTS IN THE CONTINUATION OF DRY WEATHER MONDAY
UNDER THE INFLUENCE OF UPPER RIDGING AND EAST COAST SURFACE
RIDGING. SHIFTS OF THE SURFACE HIGH CENTER SOUTHWARD AND
EASTWARD PROGRESSION OF A NORTHERN GREAT PLAINS TROUGH WILL
INITIATE WEAK MOIST ADVECTION THAT ALLOWS HEAT INDICES TO
APPROACH THE MID 90S WITH LOW PROBABILITY (LESS THAN 10%) OF ANY
LOCATION REACHING HEAT ADVISORY CRITERIA.
ENSEMBLE MODELS FAVOR THE NORTHERN GREAT PLAINS TROUGH TO DRIFT
ACROSS THE NORTHERN GREAT LAKES TUESDAY THROUGH THURSDAY, ACTING
TO INCREASE MID-LEVEL MOISTURE AND PROVIDE INCREASED JET
ASCENT. EROSION OF WARM AIR ALOFT COMBINED WITH INCREASED
MOISTURE SHOULD CREATE MORE WIDESPREAD CONVECTION DURING THIS
PERIOD. THERE IS UNCERTAINTY DUE TO VARIANCES IN POTENTIAL
TROUGH DEPTH/FORWARD SPEED THAT WILL INFLUENCE TIMING (TUESDAY
VS. WEDNESDAY) AND ACTUALIZED CONVECTIVE COVERAGE. LATEST
ANALYSIS SUGGESTS VERY LOW PROBABILITIES OF ANY SEVERE RISK FOR
THIS PERIOD DUE TO HIGH LIKELIHOOD OF WEAK SHEAR AND MARGINAL
CAPE DEVELOPMENT, BUT POTENTIAL FOR PWATS TO APPROACH 90TH
DAILY PERCENTILES SUGGESTS A NON-ZERO FLOOD THREAT.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
A WEAK UPPER TROUGH WILL CONTINUE TO SUPPORT A FEW MID AND HIGH
LEVEL CLOUDS THIS MORNING. SOME VIS RESTRICTIONS TO HIGH-END
MVFR HAVE CREPT INTO A FEW SITES THIS MORNING WITH SOME
REPORTING HAZE. THIS COULD BE SOME TRAPPED WILDFIRE SMOKE
BENEATH THE NOCTURNAL INVERSION THAT SHOULD DISSIPATE WITH
MIXING QUICKLY AFTER SUNRISE.
THE TROUGH WILL SHIFT SLOWLY EAST LATER THIS MORNING AS RIDGING
BEGINS TO BUILD IN. THE CU RULE AND MODEL SOUNDINGS INDICATE A
SCATTERED (TO LOCALLY BROKEN) DIURNAL CUMULUS LAYER AFTER
SUNRISE THROUGH EARLY EVENING. WIND SHOULD BE FROM THE SE AT
LESS THAN 10KT THROUGH THE PERIOD.
OUTLOOK...
VFR IS EXPECTED THROUGH MONDAY UNDER A RIDGE OF HIGH PRESSURE.
LOW CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN TUESDAY AS A
COLD FRONT APPROACHES.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...FRAZIER
NEAR TERM...FRAZIER
SHORT TERM...FRAZIER
LONG TERM...FRAZIER
AVIATION...WM/MLB
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