268
FXUS61 KPBZ 201847
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
247 PM EDT WED AUG 20 2025
SYNOPSIS
SCATTERED SHOWER AND THUNDERSTORM CHANCES CAN BE EXPECTED WITH THE
PASSAGE OF A WEAK COLD FRONT THROUGH TONIGHT. DAYTIME TEMPERATURES
WILL LOWER TO NEAR NORMAL TODAY BEFORE GRADUALLY INCREASING TO THE
UPPER 80S BY SATURDAY. SUNDAY, AN UPPER LEVEL TROUGH WILL BRING A
COLD FRONT THROUGH ALLOWING TEMPERATURES TO DROP BELOW NORMAL BY
MONDAY.
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/
KEY MESSAGES:
- COLD FRONT AND ASSOCIATED UPPER TROUGH BRINGS SCATTERED
SHOWERS/STORMS THIS AFTERNOON INTO THE EVENING.
- OVERNIGHT LOW TEMPERATURES REMAIN ABOVE NORMAL.
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SCATTERED SHOWERS WILL CONTINUE INTO THE EVENING MAINLY EAST OF I-
79. AMONG THESE SHOWERS, THE CHANCE FOR THUNDERSTORMS WILL REMAIN IN
EASTERN FAYETTE COUNTY AND NORTHERN WEST VIRGINIA. TONIGHT, THE LOW
TEMPERATURES WILL BE WELL ABOVE NORMAL BY 2F-5F DUE TO CLOUD
COVERAGE AND CONTINUED LOW LEVEL MIXING/TURBULENCE.
SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/
KEY MESSAGES:
- SCATTERED SHOWER/STORM CHANCES CONTINUE THROUGH THE AFTERNOON
AND INTO THURSDAY WITH THE PASSAGE OF A FRONT AND ASSOCIATED
UPPER TROUGH.
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SCATTERED RAIN CHANCES WILL DECREASE IN THE WAKE OF THE FRONT
BY THIS AFTERNOON/EVENING. ALL INDICATIONS ARE THAT
PRECIPITATION WILL BE WIDELY SCATTERED, WITH QPF AMOUNTS BETWEEN
0.10" TO 0.50" IN GENERAL. ANOMALOUSLY HIGH PWATS COULD THOUGH
RESULT IN LOCALIZED AREAS OF HIGHER AMOUNTS ASSOCIATED WITH
DEEPER CONVECTION, SO LOCALIZED FLASH FLOODING CAN'T BE
COMPLETELY RULED OUT.
RENEWED HIGH PRESSURE ACROSS THE GREAT LAKES AND OHIO VALLEY SHOULD
KEEP MOST OF THE AREA DRY OVERNIGHT INTO THURSDAY. SOME WEAK
TROUGHING COULD HELP TO INITIATE A FEW DIURNAL SHOWERS
THURSDAY AFTERNOON. WITH HURRICANE ERIN TO OUR EAST, FLOW WILL
BE OUT OF THE NORTHEAST ON THURSDAY.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
KEY MESSAGES:
- ABOVE AVERAGE TEMPERATURES RETURN BY THIS WEEKEND
- PRECIPITATION CHANCES RETURN SATURDAY INTO SUNDAY WITH A
PASSING COLD FRONT
- COOLER WEATHER BEGINS NEXT WEEK.
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RIDING OVER THE OHIO RIVER VALLEY WILL RESULT IN DRY CONDITIONS
AND WARMER CONDITIONS TOWARDS THE END OF THE WEEK AND INTO THE
WEEKEND BEFORE A PASSING COLD FRONT AND AN UPPER- LEVEL TROUGH
INCREASE CHANCES OF PRECIPITATION SATURDAY INTO SUNDAY. OVERALL,
RAINFALL AMOUNTS CONTINUE TO LOOK RELATIVELY LOW (30-40% OF
>0.25" FOR COUNTIES ALONG THE APPALACHIAN RIDGE-LINE AND LESS
THAN 25% CHANCE WEST OF PITTSBURGH).
GENERALLY HIGH CONFIDENCE EXISTS IN PERSISTENT EASTERN CONUS
TROUGHING BY EARLY NEXT WEEK. THIS SHOULD KEEP TEMPERATURES
BELOW AVERAGE DURING THE FIRST HALF OF NEXT WEEK.
AVIATION /19Z WEDNESDAY THROUGH MONDAY/
THE PASSAGE OF A WEAK SURFACE FRONT AND UPPER SAGGY TROUGH WILL
FAVOR ISOLATED SHOWERS AROUND MGW THROUGH 21Z BEFORE BEING
RELEGATED TO THE HIGHER TERRAIN EAST OF THAT TERMINAL. THOUGH
THE LOSS OF THE FRONT AND DIURNAL HEATING SHOULD ALLEVIATE
PRECIPITATION CONCERNS, AN ISOLATED SHOWER TO PATCHY DRIZZLE MAY
DEVELOP THROUGH THE OVERNIGHT PERIOD INTO THURSDAY DUE TO BROAD
ASCENT AMID ABUNDANT MOISTURE (WITH SOME INFLUENCE MOVING AROUND
THE TROPICAL SYSTEM ERIN).
IMPACTS WILL BE FOCUSED ON CEILINGS WHICH WILL SHOW AN
IMPROVEMENT PROGRESSION TOWARDS VFR (OR HIGH MVFR) THROUGH 00Z
BEFORE GRADUALLY LOWERING OVERNIGHT. TIMING OF IMPROVEMENTS MAY
VARY AN HOUR, BUT CONFIDENCE IS HIGHER ON THIS ASPECT; LOWER
CONFIDENCE EXISTS IN THE TIMING OF LOWERING CIGS (AND LOW
PROBABILITY FOG POTENTIAL) BETWEEN 03Z-12Z AS SOME NNE BOUNDARY
LAYER WIND MAY DISRUPT STRATUS FORMATION OR ACCELERATE STRATUS
ADVECTION SW. THERE IS HIGH CONFIDENCE (70-90% PROBABILITY) IN
IFR CIGS BY 12Z AT ALL TERMINALS SAVE MGW/LBE WHICH MAY EXHIBIT
SLIGHTLY HIGHER CIGS DUE TO DOWNSLOPE EFFECTS OF AN EAST WIND.
CIGS WILL RISE WITH DIURNAL HEATING/MIXING THURSDAY.
OUTLOOK...
HIGH PRESSURE NUDGING INTO THE REGION FROM THE WEST WILL AIDE IN
GRADUAL CIG IMPROVEMENTS TOWARD VFR THURSDAY AFTERNOON. HOWEVER,
RESIDUAL MOISTURE PLUS SOME INFLUENCE FROM THE ATLANTIC TROPICAL
SYSTEM MAY AID AN ISOLATED SHOWER THAT BRIEFLY STALL THOSE
IMPROVEMENTS.
HIGH CONFIDENCE IN VFR RETURNS FRIDAY AS HIGH PRESSURE BROADENS
ACROSS THE OHIO RIVER VALLEY. SHOWER AND THUNDERSTORM CHANCES
RETURN SATURDAY EVENING INTO SUNDAY WITH THE PASSAGE OF A
NOTABLE SURFACE COLD FRONT AND UPPER TROUGH.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...LUPO
NEAR TERM...LUPO
SHORT TERM...88/LUPO
LONG TERM...RACKLEY/88/LUPO
AVIATION...FRAZIER
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