661
FXUS61 KPBZ 050600
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
200 AM EDT WED AUG 5 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES WERE MADE TO THE LATEST FORECAST.
KEY MESSAGES
1) AN UNSETTLED PATTERN RETURNS TODAY, WITH DAILY SHOWER AND
THUNDERSTORM CHANCES INTO EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
A BROAD UPPER TROUGH IS EXPECTED TO ADVANCE EASTWARD TODAY, AS
ANOTHER TROUGH ACROSS THE TENNESSEE VALLEY DRIFTS NORTHWARD.
INCREASING MOISTURE AND DIURNALLY DRIVEN INSTABILITY SHOULD
RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPMENT BY THE
AFTERNOON. ML CAPE IS PROGGED TO BE AROUND 1000 J/KG, WITH WEAK
SHEAR (10-20KT) IN PLACE. WHILE OVERALL SEVERE STORM POTENTIAL
IS LIMITED, A FEW GUSTY STORMS WITH HEAVY DOWNPOURS WILL BE
POSSIBLE. THE SOUTHERN STREAM LOW IS PROGGED TO PHASE WITH THE
APPROACHING TROUGH TONIGHT. MOISTURE AND LIMITED SHORTWAVE
SUPPORTED LIFT SHOULD STILL RESULT IN SCATTERED SHOWERS ACROSS
THE AREA, WITH A THUNDERSTORM STILL POSSIBLE WITH LIMITED
ELEVATED INSTABILITY.
ANOTHER SHORTWAVE EMBEDDED IN THE BROAD UPPER TROUGH IS PROGGED
TO TRACK ACROSS THE REGION ON THURSDAY, WITH ADDITIONAL SHOWERS
AND THUNDERSTORMS. INSTABILITY AND SHEAR VALUES ARE EXPECTED TO
BE SIMILAR TO TODAY, WITH A SIMILAR MESSAGE OF POSSIBLE GUSTY
THUNDERSTORMS AND HEAVY DOWNPOURS. THIS ACTIVITY SHOULD AGAIN
DIMINISH AFTER SUNSET, THOUGH SCATTERED SHOWERS/ISOLATED STORMS
ARE STILL EXPECTED. EXISTING CLOUD COVER WILL HAVE AN IMPACT ON
THE AMOUNT OF DIURNALLY DRIVEN INSTABILITY.
A STRONGER SHORTWAVE IS PROGGED FOR A FRIDAY PASSAGE, WITH
HIGHER CHANCES FOR SHOWERS AND THUNDERSTORMS. INSTABILITY IS
PROGGED TO BE SLIGHTLY HIGHER, WITH AN ML CAPE AROUND 1500 J/KG,
WITH SIMILAR 0-6KM SHEAR AROUND 20KT. MORE UNCERTAINTY IN
SHORTWAVE LOCATION AND TIMING EXISTS OVER THE WEEKEND. IN
GENERAL, BROAD UPPER TROUGHING AND SURFACE HEATING SHOULD RESULT
IN DAILY SCATTERED SHOWER/STORM CHANCES. ANOTHER STRONG
SHORTWAVE AND COLD FRONT APPROACH AND PASSAGE IS INDICATED FOR
MONDAY INTO TUESDAY IN MODEL ENSEMBLES, WITH CONTINUED
SHOWERS AND THUNDERSTORMS.
OVERALL UNCERTAINTY EXISTS IN THE DAILY CHANCES FOR SEVERE
STORMS AND LOCALLY HEAVY RAINFALL. THIS POTENTIAL WILL DEPEND ON
THE AMOUNT OF CLOUD COVER, SURFACE HEATING, OUTFLOWS FROM
PREVIOUS CONVECTION, ETC. AT THIS TIME THE OVERALL POTENTIAL FOR
SEVERE STORMS AND FLOODING THROUGH THE WEEKEND IS LOW. THIS WILL
BE MONITORED OVER THE UPCOMING DAYS FOR ANY INCREASE IN
POTENTIAL OF THUNDERSTORM HAZARDS.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
VFR IS EXPECTED THROUGH THIS MORNING AHEAD OF AN APPROACHING
SHORTWAVE TROUGH. INCREASING MOISTURE AND ASCENT AHEAD OF THIS
TROUGH, ALONG WITH DIURNALLY DRIVEN INSTABILITY, WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BY THIS
AFTERNOON. INCLUDED A PROB30 MENTION AT ALL SITES FOR THIS
AFTERNOON INTO EARLY EVENING. A FEW SHOWERS/ISOLATED STORMS
SHOULD CONTINUE OVERNIGHT, THOUGH COVERAGE SHOULD BE MINIMAL.
INCLUDED A VCSH MENTION FOR THIS POTENTIAL OVERNIGHT.
OUTLOOK...
PERIODIC SHORTWAVES TRACKING THROUGH THE UPPER TROUGH SHOULD
RESULT IN DAILY SHOWER AND THUNDERSTORM CHANCES THROUGH SUNDAY,
ESPECIALLY IN THE AFTERNOON AND EVENING. THERE IS ALSO A
POTENTIAL FOR PATCHY MORNING FOG AND STRATUS WITH LOW LEVEL
MOISTURE IN PLACE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...WM
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