769
FXUS61 KPBZ 271136
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
736 AM EDT THU AUG 27 2026
WHAT HAS CHANGED
INCREASED THE COVERAGE OF EARLY MORNING SHOWERS ACROSS THE AREA
TODAY. CHANCES FOR CONVECTION HAS ALSO DECREASED SLIGHTLY THIS
AFTERNOON. OTHERWISE NO MAJOR CHANGES TO THE FORECAST.
KEY MESSAGES
1) ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TODAY. THERE
IS A MARGINAL RISK FOR SEVERE STORMS THIS AFTERNOON AND EARLY
EVENING MAINLY EAST OF PITTSBURGH
2) DRY WEATHER RETURNS FRIDAY THROUGH THE WEEKEND, BEFORE
ADDITIONAL SHOWER AND THUNDERSTORM CHANCES RETURN EARLY NEXT
WEEK.
DISCUSSION
KEY MESSAGE 1...
A LEAD SHORTWAVE IN A BROAD UPPER TROUGH WILL CROSS THE EASTERN
GREAT LAKES AND UPPER OHIO VALLEY REGION THIS MORNING. ISOLATED
SHOWERS, AND POSSIBLY A THUNDERSTORM, ARE EXPECTED WITH THIS
TROUGH MAINLY TO THE NORTH OF PIT WHERE MORE FAVORABLE MOISTURE
WAS LOCATED. THIS SHORTWAVE IS EXPECTED TO BE THE FOCUS FOR A MORE
FAVORABLE SEVERE WEATHER POTENTIAL EAST OF THE AREA THIS
AFTERNOON.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
REDEVELOP THIS AFTERNOON ACROSS THE AREA WITH THE APPROACH AND
PASSAGE OF A COLD FRONT. A LACK OF DEEP LAYER MOISTURE WILL
LIKELY LIMIT THUNDERSTORM COVERAGE, WITH DRY AIR ENTRAINMENT
ALSO LIMITING UPDRAFT STRENGTH. WARMING IN THE MID LEVELS COULD
ALSO LIMIT THUNDERSTORM DEVELOPMENT, AND THE SEVERE WEATHER
POTENTIAL THIS AFTERNOON. THE DRY AIR ALOFT COULD ENHANCE
DOWNDRAFTS FOR ANY STORMS THAT ARE ABLE TO BECOME MORE ORGANIZED
THROUGH THE AFTERNOON AND EARLY EVENING. ENSEMBLES INDICATE ML
CAPE MAINLY BETWEEN 1000 AND 1500 J/KG THIS AFTERNOON, WITH
0-6KM SHEAR AROUND 20KT. THE STORM PREDICTION CENTER HAS
MAINTAINED A MARGINAL RISK FOR SEVERE STORMS ACROSS PORTIONS OF
THE AREA, MAINLY EAST OF A FKL-PIT-CDI LINE.
CONVECTION SHOULD QUICKLY WANE THIS EVENING WITH THE LOSS OF
INSTABILITY, AND THE PASSAGE OF THE COLD FRONT.
KEY MESSAGE 2...
THE COLD FRONT IS EXPECTED TO EXIT THE REGION TONIGHT, WITH
PARTIAL CLEARING IN THE EVENING. AREAS OF FOG AND STRATUS ARE
THEN EXPECTED TO DEVELOP OVERNIGHT INTO EARLY FRIDAY MORNING,
ESPECIALLY WHERE RAIN OCCURS THIS AFTERNOON.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD UNDER BROAD TROUGHING
ALOFT ON FRIDAY, WITH DRY WEATHER EXPECTED. THIS TREND SHOULD
CONTINUE INTO THE WEEKEND, AS THE SURFACE HIGH TRACKS EAST
ACROSS THE REGION. RISING 500MB HEIGHTS SHOULD ALSO RESULT IN A
GRADUAL WARMING TREND OVER THE WEEKEND AS WELL.
AN UPPER HIGH IS PROGGED TO DEVELOP ACROSS THE SOUTHEAST CONUS
BY EARLY NEXT WEEK. MODELS DIFFER ON THE STRENGTH OF THIS
HIGH/RIDGE, AND ITS NORTHERN EXTENT. CURRENT INDICATIONS ARE A
SERIES OF SHORTWAVES ARE EXPECTED TO TRACK ALONG THE NORTHERN
PERIPHERY OF THE HIGH, WHICH SHOULD RETURN LOW CHANCES FOR
SHOWERS AND THUNDERSTORMS TO PORTIONS OF THE AREA MONDAY AND
TUESDAY. INCREASING 500MB HEIGHTS SHOULD ALSO RESULT IN ABOVE
AVERAGE TEMPERATURES INTO THE MIDDLE OF NEXT WEEK. ENSEMBLES
INDICATE THE RIDGE SHOULD FLATTEN TOWARD MID WEEK, WITH
INCREASING SHOWERS AND STORM CHANCES.
AVIATION /12Z THURSDAY THROUGH MONDAY/
A COLD FRONT CROSSES THE AREA THIS AFTERNOON AND EVENING.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP AS THE FRONT APPROACHES, ALONG WITH A SCATTERED TO
BROKEN CUMULUS CLOUD DECK. MLCAPE FROM 1000-1500 J/KG IS
EXPECTED THIS AFTERNOON, WITH 0-6KM SHEAR AROUND 20KT. A LACK OF
DEEP LAYER MOISTURE, AND WEAKENING LAPSE RATES ALOFT WITH
WARMING IN THE MID LEVELS, WILL LIKELY LIMIT THUNDERSTORM
COVERAGE. MAINTAINED A PROB30 MENTION FOR THE MOST LIKELY TIME
TO SEE THUNDERSTORMS THIS AFTERNOON. THE DRY AIR ALOFT COULD
RESULT IN GUSTY DOWNDRAFTS IF STORMS ARE ABLE TO BECOME
ORGANIZED. ANY THUNDERSTORMS SHOULD QUICKLY DIMINISH THIS
EVENING WITH WANING INSTABILITY.
PARTIAL CLEARING IS EXPECTED AFTER FROPA THIS EVENING, THOUGH
THAT MAY BE SHORT-LIVED. ENSEMBLE GUIDANCE CONTINUES TO HIT
PROBABILITIES FOR WIDESPREAD FOG PRETTY HARD OVERNIGHT DUE TO
LINGERING LOW-LEVEL MOISTURE AND CALMING SURFACE WINDS BENEATH A
NOCTURNAL INVERSION. FOR NOW, ONLY MENTIONED VISIBILITIES BELOW
A MILE AT FKL/DUJ WHERE CONFIDENCE IN DENSE FOG IS HIGHER.
ELSEWHERE, INTRODUCED IFR VISIBILITIES AFTER 06Z-08Z TIMEFRAME,
BUT IF MODELS CONTINUE TO TREND LOWER THROUGH THE DAY, THOSE MAY
NEED TO BE REDUCED TO A MILE OR LOWER AT MORE TERMINALS.
OUTLOOK...
OUTSIDE OF EARLY MORNING FOG/STRATUS, VFR IS EXPECTED THROUGH
THE WEEKEND AS SURFACE HIGH PRESSURE MOVES EAST ACROSS THE
REGION. LOW CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN MONDAY
WITH AN APPROACHING SHORTWAVE TROUGH.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...CERMAK
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