507
FXUS61 KPBZ 240627
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
227 AM EDT SUN MAY 24 2026
WHAT HAS CHANGED
FLOOD WATCH EXPIRED AT 2AM. MONITORING THE POTENTIAL FOR
LOCALLY HEAVY RAINFALL THIS AFTERNOON AND EVENING WITH A
CROSSING SHORTWAVE TROUGH. NO OTHER MAJOR CHANGES TO THE
FORECAST AT THIS TIME.
KEY MESSAGES
1) SHOWERS/THUNDERSTORMS EXPECTED TO INCREASE TODAY INTO
TONIGHT
2) SHOWER/THUNDERSTORM CHANCES CONTINUE AT TIMES INTO THE
MIDDLE OF NEXT WEEK MAINLY SOUTH OF I-80. DRY AND SEASONABLE BY
LATE WEEK
DISCUSSION
KEY MESSAGE 1...
SCATTERED SHOWERS WILL CONTINUE EARLY THIS MORNING AHEAD OF A
SURFACE BOUNDARY CURRENTLY ACROSS EASTERN OHIO. THE BOUNDARY
SHOULD DISSIPATE LATER THIS MORNING. LET THE CURRENT FLOOD
WATCH EXPIRE AT 2AM, WITH RAINFALL RATES LIGHT ENOUGH TO NOT
RESULT IN FLOODING THIS MORNING.
WATER VAPOR IMAGERY AND THE LATEST MODELS SHOW THE NEXT
SHORTWAVE TO OUR W AND SW. THIS WAVE WILL ADVANCE NORTHEASTWARD
TODAY, CROSSING THE UPPER OHIO VALLEY REGION LATER TODAY INTO
TONIGHT. SHOWERS WILL BECOME MORE NUMEROUS ACROSS THE REGION
WITH THE APPROACH OF THE SHORTWAVE. HREF ML CAPE SHOWS 500-750
J/KG THIS AFTERNOON, WITH AROUND 30KT OF 0-6KM SHEAR, SO A FEW
THUNDERSTORMS WILL BE POSSIBLE AS WELL. PWATS INCREASE TO
AROUND 1.6 IN THIS AFTERNOON AND EVENING. WHILE THERE REMAINS A
POTENTIAL FOR FLOODING, ESPECIALLY ACROSS EASTERN OHIO, CAMS
INDICATE HEAVIER CELLS COULD BE SCATTERED WITH SUFFICIENT
MOVEMENT TO PRECLUDE A WIDESPREAD FLOOD/FLASH FLOOD POTENTIAL.
WILL HIGHLIGHT THIS POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK,
AND MONITOR FOR THE NEED FOR ANY FLOOD OR FLASH FLOOD WATCHES.
INSTABILITY SHOULD DIMINISH AFTER SUNSET, THOUGH NUMEROUS
SHOWERS/ISOLATED THUNDERSTORMS WILL CONTINUE AS THE SHORTWAVE
CROSSES THE REGION. PROBABILITIES RANGE FROM 50-60 PERCENT OF 1
INCH OF RAIN OVER 24 HRS FOR AREAS SOUTH OF I-80, WITH LESSES
AMOUNTS TO THE NORTH.
KEY MESSAGE 2...
THE SHORTWAVE TROUGH SHOULD BEGIN TO EXIT THE REGION MONDAY
MORNING, THOUGH THE LINGERING SURFACE TROUGH IS EXPECTED TO SET
UP ACROSS THE MID ATLANTIC TO THE LOWER OHIO VALLEY REGION
LATER IN THE DAY. MOST OF THE DAY SHOULD BE DRY NORTH OF I-70,
WITH SHOWER/THUNDERSTORM CHANCES CONTINUING TO THE SOUTH IN
CLOSER PROXIMITY TO THE TROUGH.
THE FLOW ALOFT IS EXPECTED TO BE FROM THE WEST, PARALLEL TO THE
BOUNDARY, THROUGH MID WEEK. THIS WILL KEEP THE BOUNDARY IN
PLACE, AND BRING PERIODIC SHOWER AND THUNDERSTORM CHANCES TO THE
REGION. THE CHANCE FOR RAIN PEAKS WEDNESDAY INTO WEDNESDAY
NIGHT AS A SHORTWAVE TROUGH ADVANCES SOUTHEASTWARD OUT OF CANADA
AND CROSSES THE UPPER OHIO VALLEY REGION. RESULTING NW FLOW
BEHIND THE SHORTWAVE SHOULD DRIVE THE SURFACE BOUNDARY OUT OF
THE AREA BY LATE THURSDAY. NW FLOW AND BUILDING HIGH PRESSURE
SHOULD RETURN DRY AND SEASONABLE WEATHER TO THE AREA BY LATE
WEEK.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
THE COLD FRONT HAS STALLED JUST TO THE WEST OVER WESTERN OHIO.
AHEAD OF IT, SHOWERS WILL CONTINUE TO STREAM NORTHEASTWARD
THROUGH THE OVERNIGHT. MVFR AND IFR CIGS WILL SLOWLY DETERIORATE
THROUGH THE OVERNIGHT AS CIGS LOWER. EXPECT LIFR AND BELOW AT
MOST TERMINALS THROUGH THE OVERNIGHT. THESE LOW CIGS WILL
CONTINUE INTO THE DAY. ANY SHOWER ACTIVITY MAY DROP VISIBILITY
BELOW MVFR VALUES. BY THE LATE AFTERNOON TOMORROW SHOWERS AND
THUNDERSTORMS WILL REDEVELOP WITH THE DAYS HEATING. THUS, WILL
EXPECT CONTINUED RESTRICTIONS THROUGH THE DAY. HAVE ADDED A
PROB30 TO TERMINALS BETWEEN 19Z TO 02Z.
A SLIGHT IMPROVEMENT TO CIGS IS POSSIBLE WITH THE THUNDERSTORM
POTENTIAL BEFORE LOWERING AGAIN TOMORROW NIGHT. GUSTY WINDS THIS
PAST EVENING WILL BEGIN TO BECOME LIGHT AND VARIABLE THROUGH THE
NIGHT AND MUCH OF THE DAY TOMORROW. CIGS DROPPING BELOW MVFR
ACROSS THE AREA THROUGH THE TAF PERIOD IS AT LEAST 70% TO 80%.
OUTLOOK...
CIGS COULD REMAIN IFR UNTIL MID-MORNING ON MEMORIAL DAY. WIDESPREAD
RAIN SHOWERS LATE SUN AFTERNOON WILL TAPER OFF WEST TO EAST
LATE SUN NIGHT, LEAVING A NEAR-SATURATED BOUNDARY LAYER.
RESTRICTIONS IN VSBY (POTENTIALLY LIFR OR LESS) ARE POSSIBLE
BY EARLY MON MORNING, ESPECIALLY IN LOCALIZED AREAS WHERE
ABUNDANT RAINFALL OCCURS ON SUN AFTERNOON/EVENING.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...SHALLENBERGER
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