639
FXUS61 KPBZ 090611
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
211 AM EDT SUN AUG 9 2026
WHAT HAS CHANGED
NO MAJOR CHANGES TO THE FORECAST HAVE BEEN MADE, AS WE REMAIN ON
TRACK FOR AN ACTIVE WEATHER PATTERN THROUGH MUCH OF THE WEEK.
KEY MESSAGES
1) REMAINING THUNDERSTORMS WILL EXIT TO THE EAST PRIOR TO
SUNRISE. A DRY REPRIEVE IS THEN FORECAST FOR THE DAYTIME HOURS.
2) DAILY SHOWER AND THUNDERSTORM CHANCES RETURN MONDAY AND
REMAIN IN THE FORECAST THROUGH AT LEAST THURSDAY WITH BOTH THE
POTENTIAL FOR STRONG/SEVERE STORMS AND HEAVY RAINFALL.
DISCUSSION
KEY MESSAGE 1...
THUNDERSTORMS CONTINUE TO THE SOUTH AND EAST OF PITTSBURGH
DURING THESE PREDAWN HOURS, AS ELEVATED INSTABILITY CONTINUES
AHEAD OF AN ADVANCING SHORTWAVE TROUGH. LOW, BUT NON-ZERO RISK
FOR GUSTY TO MARGINALLY SEVERE WIND WILL CONTINUE WITH THESE
STORMS UNTIL THEY EXIT THE REGION BY 09Z OR SO, AS THE
SHORTWAVE DEPARTS AND A SURFACE BOUNDARY ENTERS THE REGION.
AFTER THE STORMS EXIT, CLEARING AND A MOIST GROUND MAY ALLOW FOR
PATCHY FOG/STRATUS DEVELOPMENT IN THE HOURS LEADING UP TO
SUNRISE, ESPECIALLY IN LOCATIONS THAT RECEIVED HEAVY RAINFALL.
THESE WOULD MIX OUT BY MID-MORNING.
AFTER SUNRISE, SURFACE RIDGING AND MID-LEVEL CAPPING WILL
SUPPRESS CONVECTIVE DEVELOPMENT THROUGH SUNDAY AND INTO THE
EVENING, PROVIDING A WELCOME BREAK FROM THE DAILY STORM CHANCES.
THIS WILL OCCUR EVEN AS THE FRONT POTENTIALLY STALLS IN OUR
REGION, WHICH WILL LIKELY HAVE IMPLICATIONS BEYOND TODAY. A
DROP IN DEWPOINTS, MAINLY INTO THE MID 60S, WILL ALSO PROVIDE A
REPRIEVE FROM THE STICKY CONDITIONS.
KEY MESSAGE 2...
DAILY SHOWER AND THUNDERSTORMS CHANCES RETURN FOR MONDAY AND
BEYOND. VERY BROAD TROUGHING WILL REMAIN IN PLACE UNTIL AT
LEAST WEDNESDAY BEFORE A STRONGER SHORTWAVE DEEPENS THE TROUGH
OVER THE GREAT LAKES. WITH PREVAILING W-NW FLOW AND DISTURBANCES
PASSING THROUGH THE UPPER PATTERN, THERE WILL BE DAILY CHANCES
FOR SHOWERS AND THUNDERSTORMS, WITH THE POTENTIAL FOR MORE
ORGANIZED CONVECTIVE COMPLEXES AS HINTED TO IN SOME OF THE
GUIDANCE.
THE FIRST OF THESE, OCCURRING LATE SUNDAY NIGHT INTO MONDAY
MORNING, APPEARS MOST LIKELY TO DIVE ITS MOST IMPACTFUL STORMS
WEST OF THE CWA, INTO CENTRAL/WESTERN OHIO, ACCORDING TO MOST OF
THE HREF COMPONENT MEMBERS. AT LEAST SCATTERED SHOWERS AND
STORMS MAY ARRIVE AFTER 06Z, BUT ARE MOST LIKELY TO REMAIN NON-
SEVERE GIVEN THE TIME OF DAY/LIKELY LACK OF SUFFICIENT
INSTABILITY.
EXACTLY WHAT HAPPENS LATER ON MONDAY REMAINS MURKY, AND WILL
LARGELY DEPEND ON THE ENVIRONMENT/BOUNDARIES LEFT BEHIND BY THE
MORNING COMPLEX, AS WELL AS POTENTIAL REINVIGORATION OF ITS
REMNANTS. ALSO, THE POSITION OF THE FRONT THAT STALLS IN OUR
REGION TODAY MAY PLAY A ROLE IN DETERMINING WHERE THE BEST
CHANCES FOR ADDITIONAL DEVELOPMENT MAY OCCUR. THE ENVIRONMENT
WILL CERTAINLY BE SUFFICIENT TO SUPPORT SEVERE STORMS, WITH
1500-2500 J/KG OF MLCAPE POSSIBLE, AND WITH AROUND 30 KNOTS OF
0-6KM SHEAR SUPPORTING STORM ORGANIZATION. DAMAGING WIND GUSTS
REMAIN THE PRIMARY THREAT, BUT HAIL AND TORNADO RISKS ALSO ARE
PRESENT. ALSO OF NOTE: GIVEN THE CONTINUED PRESENCE OF ABOVE-
NORMAL PRECIPITABLE WATER VALUES IN A CLIMATOLOGIC SENSE, AS
WELL AS THE POTENTIAL FOR SOME TRAINING STORMS ALONG THE
BOUNDARY, WPC CONTINUED TO HIGHLIGHT OUR REGION IN A SLIGHT
(LEVEL 2 OF 4) RISK FOR EXCESSIVE RAIN FOR MONDAY INTO MONDAY
NIGHT. THE EVENTUAL NEED FOR A FLOOD WATCH CANNOT BE RULED OUT.
SEVERE/HEAVY RAIN RISKS CONTINUE FOR TUESDAY AND POTENTIALLY
INTO WEDNESDAY AS WELL, AS THE BOUNDARY MAY CONTINUE TO WAVER
AROUND THE AREA IN A MOIST, UNSTABLE AIR MASS. MACHINE-LEARNING
GUIDANCE IS IN SUPPORT OF THIS. THE STRONGER GREAT LAKES
SHORTWAVE MAY FINALLY PUSH THE BOUNDARY DEFINITIVELY SOUTH OF
THE REGION BY THURSDAY/FRIDAY, LEADING TO LESS THREATENING
WEATHER.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
REMAINING THUNDERSTORM ACTIVITY WILL EXIT THE REGION BY 09Z AS A
SHORTWAVE EXITS THE REGION, AND AS A WEAK FRONT DROPS INTO THE
REGION. MGW IS THE LONE TERMINAL THAT MAY EXPERIENCE MVFR/IFR
IMPACTS FROM HEAVY RAIN FROM THESE AT THIS POINT. CLEARING SKY
AND LIGHT WIND MAY LEAD TO PATCHY MVFR/IFR FOG AND STRATUS
DEVELOPMENT LEADING UP TO SUNRISE. CONFIDENCE IN TIMING AND
COVERAGE OF THESE RESTRICTIONS REMAINS FAIRLY LOW CONFIDENCE.
ANY RESTRICTIONS SHOULD IMPROVE BY 15Z DUE TO DAYTIME MIXING.
VFR CONDITIONS ARE THEN CONFIDENTLY FORECAST FOR THE REMAINDER
OF THE TAF PERIOD AS SURFACE RIDGING AND MID-LEVEL CAPPING
PREVENT CONVECTIVE DEVELOPMENT THROUGH THIS EVENING.
OUTLOOK...
ACTIVE WEATHER RETURNS MONDAY THROUGH THE LATER HALF OF THE WEEK
WITH VARYING ROUNDS OF SHOWERS AND THUNDERSTORMS. TIMING OF
STORMS FOR A GIVEN DAY IS LIKELY TO BE OF LOWER CONFIDENCE AND
DEPENDENT ON UPSTREAM STORM PROGRESSION. MOST RESTRICTIONS
DURING THIS PERIOD WILL BE TIED TO STORM ACTIVITY AND/OR MORNING
FOG/STRATUS RESULTANT OF RAIN PLUS OVERNIGHT CLEARING.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...FRAZIER/CL
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