494
FXUS61 KPBZ 010037
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
837 PM EDT FRI JUL 31 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST.
KEY MESSAGES
1) CONTINUED DRY THROUGH PART OF SATURDAY
2) SHOWERS AND THUNDERSTORMS RETURN LATE SATURDAY AND SUNDAY,
WITH UNSETTLED WEATHER NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
ALTHOUGH A FEW DEEPER SHOWERS ATTEMPTED TO DEVELOP WITHIN THE
DEEPLY MIXED BOUNDARY LAYER IN ERN OH, WHERE DEWPOINTS ARE IN
THE MID 60S, EAST OF THE WV BORDER IS LIKELY TO REMAIN DRY
THROUGH AT LEAST EARLY SAT AS A RESULT OF LOWER DEWPOINTS AND
HIGH PRESSURE MOVING ACROSS THE REGION. A DIGGING SHORTWAVE
TROUGH IN THE CENTRAL CONUS IS EXPECTED TO ADVANCE EWD TONIGHT
INTO SAT, SPREADING MID- AND UPPER-LEVEL CLOUDS INTO THE UPPER
OH VALLEY THRU SAT.
KEY MESSAGE 2...
INCREASING MOISTURE AND ASCENT ASSOCIATED WITH A LEAD SHORTWAVE
TROUGH SHOULD RETURN SHOWER AND THUNDERSTORM CHANCES SAT
AFTERNOON ACROSS OHIO, OVERSPREADING THE REMAINDER OF THE AREA
SAT NIGHT.
PERIODS OF SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED ON
SUN AS SURFACE LOW PRESSURE CROSSES THE REGION. AFTER AN
OVERNIGHT ROUND OF SHOWERS, CONTINUED CLOUDS COULD LIMIT SFC
HEATING WITH DETRIMENTAL IMPACTS TO RECOVERY/BUOYANCY. MLCAPE
CURRENTLY IS PROGGED AT 1000 J/KG OR LESS, HOWEVER, VERTICAL
WIND SHEAR UP TO 30 KT COULD HELP OFFSET MEAGER BUOYANCY).
IF MODEST HEATING BETWEEN THE EPISODIC RAIN SHOWERS ON SUN CAN
OCCUR, AN INCREASE IN CAPE WITHIN THE SHEARED ENVIRONMENT WOULD
IMPROVE THE PROBABILITY FOR SEVERE WEATHER TO DEVELOP.
LOCALLY HEAVY RAIN ALSO WILL BE POSSIBLE AS PWATS APPROACH 1.8
INCHES, THOUGH THE POTENTIAL DRY SLOT SUNDAY AFTERNOON AHEAD OF
THE SURFACE LOW COULD LIMIT THIS POTENTIAL. THE SURFACE COLD
FRONT IS CURRENTLY EXPECTED TO CROSS THE AREA LATE SUNDAY/SUNDAY
NIGHT.
MODEL ENSEMBLES THEN INDICATE A PERSISTENT TROUGH ACROSS THE
EASTERN GREAT LAKES AND OHIO VALLEY REGION EARLY IN THE WEEK.
THIS TROUGH SHOULD WEAKEN SOME THROUGH THE WEEK, THOUGH
SIGNIFICANT UNCERTAINTY EXISTS IN EXACT PLACEMENT AND STRENGTH.
OVERALL, EXPECT DAILY CHANCES FOR DIURNALLY DRIVEN CONVECTION
UNDER THIS PATTERN.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
HIGH CONFIDENCE VFR CONTINUES THROUGH SATURDAY AS SURFACE HIGH
PRESSURE SLIDES EAST ACROSS THE REGION. HIGH CLOUDS WILL
CONTINUE TO INCREASE THIS EVENING AND OVERNIGHT AHEAD OF THE
NEXT SHORTWAVE TROUGH. WIND WILL BE LIGHT AND VARIABLE
OVERNIGHT, LIMITED TO AROUND 5 KNOTS THROUGH THE PERIOD.
EXPECT CLOUDS TO THICKEN AND LOWER AFTER SUNRISE SATURDAY AS
THE COLUMN SATURATES. THOUGH A FEW ISOLATED SHOWERS CANNOT BE
RULED OUT, BETTER RAIN CHANCES WILL APPROACH FROM THE WEST IN
THE LATE EVENING HOURS. MOST LIKELY TOA FOR PIT IS AFTER 3AM,
THOUGH NOTABLE UNCERTAINTY STILL EXISTS WITH DISTRIBUTION AS
WIDE AS AN ARRIVAL TIME AROUND MIDNIGHT AND AS LATE AS DAYBREAK
SUNDAY.
OUTLOOK...
SHOWERS, THUNDERSTORMS, AND RELATED IFR RESTRICTIONS ARE
EXPECTED ON SUNDAY, WITH CHANCES FOR DAMAGING WIND AND
TORNADOES SUNDAY AFTERNOON AND EVENING. A LINGERING TROUGH COULD
MAINTAIN RESTRICTION POTENTIAL MONDAY AND TUESDAY WITH
SHOWER/THUNDERSTORM CHANCES, THOUGH MUCH TIMING UNCERTAINTY
ARISES INTO EARLY NEXT WEEK WITH EVOLUTION OF THE TROUGH.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...KRAMAR/WM/LUPO
AVIATION...RACKLEY/MLB
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