446
FXUS61 KPBZ 251734
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
134 PM EDT MON MAY 25 2026
WHAT HAS CHANGED
UPDATED FOR THE 18Z TAF ISSUANCE.
KEY MESSAGES
1) RAIN CHANCES AND ISOLATED STORMS EXPECTED SOUTH OF
PITTSBURGH MONDAY INTO WEDNESDAY
2) COOLER AND DRIER CONDITIONS EXPECTED LATE WEEK
DISCUSSION
KEY MESSAGE 1...
IN THE WAKE OF A PASSING COLD FRONT, DRIER CONDITIONS HAVE
DEVELOPED EARLY THIS MORNING AS CLOUDS GRADUALLY BREAK UP WITH
DIURNAL MIXING OF DRIER AIR ALOFT. SOUTH OF PITTSBURGH, THE
FRONTAL BOUNDARY HAS STALLED AND ISOLATED SHOWERS CANNOT BE
RULED OUT IN NORTHERN WEST VIRGINIA. THUNDERSTORM CHANCES,
HOWEVER, REMAIN VERY LOW.
FOR TUESDAY, SIMILAR WEATHER IS EXPECTED WITH LITTLE MOVEMENT
OF THE STALLED FRONTAL BOUNDARY TO OUR SOUTH.
BY LATE TUESDAY INTO EARLY WEDNESDAY, THE DEVELOPMENT OF A
TROUGH TO OUR NORTH COMBINED WITH THE LINGERING FRONTAL BOUNDARY
DRAPED ACROSS WEST VIRGINIA COULD LEAD TO SHOWERS AND ISOLATED
THUNDERSTORMS CAPABLE OF PRODUCING ISOLATED FLOODING FORM
TRAINING CONVECTION. IF CONFIDENCE IN HEAVIER RAINFALL AMOUNTS
CONTINUES TO INCREASE, A LOCALIZED FLOOD WATCH MAY BE NEEDED.
AT THE MOMENT, HIGH-RESOLUTION GUIDANCE DEPICTS A 30-40% CHANCE
OF AN AREA OF HEAVY RAINFALL (+1 INCH IN 6 HOURS) TO OCCUR.
HOWEVER, CONFIDENCE IS LOW ON LOCATION DUE TO THE UNCERTAINTY OF
THE FRONTAL BOUNDARY POSITION. THE THREAT FOR HEAVY RAIN WILL
DECREASE LATE WEDNESDAY MORNING WITH AN ADVANCING COLD FRONT.
KEY MESSAGE 2...
BY MIDWEEK, LONG-RANGE GUIDANCE SUGGESTS A CLOSED LOW PRESSURE
SYSTEM WILL PERSIST ALONG THE WEST COAST WHILE A RIDGE
STRENGTHENS OVER THE NORTHERN PLAINS. THIS PATTERN IS EXPECTED
TO PROMOTE DEEP NORTHWEST FLOW ACROSS THE GREAT LAKES AND
NORTHEAST UNDER A TROUGH. AS A RESULT, COOLER AND DRIER
CONDITIONS ARE ANTICIPATED LATE IN THE WEEK AND CONTINUING INTO
EARLY NEXT WEEK. THE THREAT FOR HAZARDOUS WEATHER IS CONSIDERED
LOW THURSDAY INTO MONDAY.
AVIATION /18Z MONDAY THROUGH SATURDAY/
AS EXPECTED, SKIES HAVE BEGUN TO CLEAR AND CIGS ARE ON THE WAY
UP AS DAYTIME MIXING AND DRY ADVECTION CONTINUES ACROSS THE
REGION. ON THIS CURRENT TREND, A FEW SITES MAY BOUNCE BETWEEN
HIGH END MVFR AND VFR FOR ANOTHER COUPLE OF HOURS BUT WE SHOULD
BE VFR AREA WIDE BY LATE AFTERNOON. WINDS ARE EXPECTED TO BE
NORTHERLY TODAY AND GENERALLY BELOW 10KTS.
MIXING-DRIVEN STRATOCU SHOULD DISSIPATE AFTER SUNSET AS CIRRUS
STREAMS IN ON THE NORTHERN SIDE OF A STALLED BOUNDARY SOUTH OF
US. LIGHT WINDS AND AMPLE MOISTURE NEAR THE GROUND COULD LEAD TO
AREAS OF FOG AGAIN TOMORROW MORNING. FOR NOW, THIS ACTIVITY HAS
BEEN CONTAINED IN TEMPO GROUPS WITH LOWER RESTRICTIONS IN THE
USUAL SPOTS. CONFIDENCE IN FOG AND LOW VIS TOMORROW LOOKS TO BE
HIGHEST FOR MGW AND LBE.
MUCH OF THE DAY TOMORROW LOOKS DRY WITH SCT BORDERLINE MVFR/VFR
STRATOCU. SHOWER CHANCES BEGIN TO RISE FOR MGW NEAR THE END OF
THE CURRENT 24 HR TAF PERIOD.
OUTLOOK...
THE STALLED BOUNDARY WILL KEEP PERIODIC RAIN AND RESTRICTION
CHANCES MAINLY SOUTH OF A LBE-ZZV LINE THROUGH WEDNESDAY. VFR
RETURNS AREAWIDE THURSDAY AND FRIDAY UNDER HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...WM/AK
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