624
FXUS61 KPBZ 051744
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
144 PM EDT WED AUG 5 2026
WHAT HAS CHANGED
REGIONAL OUTLOOK REMAINS UNCHANGED WITH THE MOIST AIRMASS
LINGERING INTO NEXT WEEK TO OFFER DAILY STORM CHANCES WITH
VARYING DEGREES OF HAZARDOUS WEATHER RISKS.
KEY MESSAGES
1) DIURNAL POP-UP THUNDERSTORMS FAVORING EASTERN OH TO NORTHWEST
PA HAVE LIMITED SEVERE AND FLOODING RISKS.
2) AN ACTIVE PATTERN CONTINUES, POTENTIALLY INTO THE START OF
NEXT WEEK, WITH HIGH DEGREES OF UNCERTAINTY IN HAZARDOUS
WEATHER RISKS.
DISCUSSION
KEY MESSAGE 1...
SIGNIFICANT MOISTURE ADVECTION WITH A LIFTING LOW OUT OF THE
CAROLINAS (AHEAD OF THE WESTERN GREAT LAKES TROUGH) HAS RAISED
DEWPOINTS NEAR 70 WHILE PUMPING PWAT VALUES FROM 0.91 (~25TH
PERCENTILE) ON THE 00Z SOUNDING LAST NIGHT TO 1.85 (~95TH
PERCENTILE) INCHES ON THE 12Z SOUNDING THIS MORNING. THIS MOIST
AIRMASS COMBINED WITH DIURNAL HEATING WILL FOSTER SCATTERED
SHOWERS AND THUNDERSTORMS THIS AFTERNOON THAT WANE AFTER SUNSET
TONIGHT.
FLASH FLOODING IS THE MAIN HAZARD TO MONITOR AS HIGH PWAT,
WARM-CLOUD RAIN PROCESS AND WEAK FORWARD MOTION CAN RESULT IN
LOCALIZED MAXIMA THAT EXCEED 1-2" IN A SHORT PERIOD OF TIME.
HOWEVER, WEAK SHEAR LIMITING STORM DURATION AND WEAK FORCING
LIMING STORM COVERAGE SHOULD PLAY A LARGE ENOUGH ROLE TO PREVENT
TOTALS FROM REACHING FFG (UNLESS STORMS FORM OVER URBAN OR
POOR-DRAINAGE AREAS) AND KEEP ANY SUCH OCCURRENCES VERY
LOCALIZED. ADDITIONALLY, THAT LACK OF SHEAR AND FORCING SHOULD
PREVENT DEEP STORM CORES FROM TAPPING INTO DRIER AIR ABOVE 20KFT
TO PRODUCE DOWNBURST WIND POTENTIAL; AGAIN, IT COULD OCCUR BUT
LIKELIHOOD IS LOW AND WOULD BE VERY LOCALIZED.
KEY MESSAGE 2...
THE GENERAL STORM ENVIRONMENT OUTLOOK FOR TODAY IS LIKELY TO
HOLD INTO EARLY NEXT WEEK: MOIST AIRMASS PLUS WEAK SHEAR
RESULTING IN DIURNALLY-DRIVEN THUNDERSTORMS THAT MAY HAVE
SPOTTIER COVERAGE AND LIMITED DAMAGING WIND/FLOOD RISKS. THIS IS
DUE TO THE SLOW PROGRESSION OF AN UPPER SHORTWAVE THROUGH THE
OHIO RIVER VALLEY THAT DOES LITTLE TO CHANGE THE ENTRENCHED
WARM, MOIST AIRMASS.
DUE TO WEAK FLOW, THE ASSESSMENT OF "FAVORED AREAS" AND "HAZARD
RISKS" IS LIKELY TO REMAIN MORE OF A DAY-OFF DUTY AS PRIOR DAY'S
CONVECTIVE EVOLUTION WITHIN AND UPSTREAM OF THE REGION PLAYS A
LARGER ROLE IN THAT DAY'S OUTLOOK. ADDITIONALLY, BETTER MODELING
OF SMALL-SCALE EMBEDDED WAVES WITHIN THE WEAK, BROAD EASTERN
CONUS TROUGHING IN THE DAY 1-2 RANGE MAY CAPTURE SUBTLE FEATURES
THAT COULD ENHANCE THUNDERSTORM COVERAGE AND HAZARD RISKS FOR A
GIVEN DAY OR EVEN SQUELCH SUCH OCCURRENCES. THE MOST THAT CAN BE
SAID AT THIS TIME, THEN, IS INDIVIDUALS SHOULD BE AWARE THAT
EACH DAY COULD SEE AFTERNOON/EVENING THUNDERSTORMS WORTH
MONITORING FOR POTENTIAL DAMAGING WIND AND/OR FLOOD RISKS, BOTH
WHICH SHOULD BE CLEARER THE MORNING OF.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
AND EVENING, WITH CONVECTION ALREADY INITIATING ACROSS EASTERN
OH TO START THE 18Z TAF CYCLE. GIVEN THE SCATTERED COVERAGE,
MAINTAINED PROB30S FOR IMPACTS AT AREA TERMINALS THROUGH 00Z,
AFTER WHICH CONVECTION SHOULD BEGIN TO WANE WITH THE LOSS OF
DAYTIME HEATING. A FEW SHOWERS MAY LINGER OVERNIGHT, SO ALSO
MAINTAINED VCSH TO REFLECT THAT POTENTIAL. OUTSIDE OF STORMS,
VFR CONDITIONS AND LIGHT WINDS PREVAIL.
OUTLOOK...
DAILY SHOWER AND THUNDERSTORM CHANCES EXPECTED THROUGH SUNDAY,
ESPECIALLY DURING AFTERNOON AND EVENING HOURS, AS A SERIES OF
DISTURBANCES CROSS THE UPPER OHIO VALLEY. THERE IS ALSO A
POTENTIAL FOR PATCHY FOG AND STRATUS WITH LOW LEVEL MOISTURE IN
PLACE DURING EARLY MORNING HOURS EACH DAY, ESPECIALLY IN AREAS
THAT SEE RAINFALL THE EVENING PRIOR.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...FRAZIER
AVIATION...CERMAK
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