541
FXUS61 KPBZ 261736
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
136 PM EDT TUE MAY 26 2026
WHAT HAS CHANGED
FLOOD WATCH ISSUED FOR LOCATIONS PRIMARILY ALONG AND SOUTH OF
INTERSTATE 70 DUE TO THE POTENTIAL FOR HEAVY RAIN OVERNIGHT INTO
WEDNESDAY.
KEY MESSAGES
1) FLOOD WATCH IN EFFECT FROM MIDNIGHT TONIGHT TO 10PM WEDNESDAY
AS SHOWERS/THUNDERSTORMS PRODUCING HEAVY RAIN MAY RESULT IN
FLASH FLOODING.
2) DRY AND SEASONABLE WEATHER CONDITIONS FAVORED THURSDAY
THROUGH THE WEEKEND.
DISCUSSION
KEY MESSAGE 1...
A WEAK SHORTWAVE TROUGH THAT IS SLOWLY PROGRESSING ALONG THE
WESTERN PERIPHERY OF THE ATLANTIC RIDGE CONTINUES ITS TREK
AROUND THIS FEATURE BY APPROACHING THE UPPER OHIO RIVER VALLEY
REGION LATE TONIGHT INTO WEDNESDAY. A WARM FRONT LIFTS NORTHWARD
TODAY BEFORE STALLING OVERNIGHT, IN CONJUNCTION WITH LOSS OF
NORTHERN SHORTWAVE MOVEMENT. IN ADDITION, ENOUGH NW FLOW WITH
TROUGHING NORTH OF THE AREA LENDS TO THE DEVELOPMENT OF STRONG
FRONTOGENESIS NEAR TO SOUTH OF THE I-70 CORRIDOR THAT RESULTS IN
A PROLONGED PERIOD OF LIFT/FORCING CREATING ROUNDS OF SHOWERS
AND THUNDERSTORMS STARTING TONIGHT AND CONTINUING INTO WEDNESDAY
EVENING.
THE RISK FOR FLASH FLOODING, WHICH RESULTED IN THE ISSUANCE OF A
FLASH FLOODING, IS FUELED BY THE COMBINATION OF FAIRLY
SATURATED GROUNDS FROM RECENT RAINS (THOUGH NOT ANOMALOUSLY SO)
AND A STORM ENVIRONMENT THAT IS CONDUCIVE TO HEAVY RAIN PLUS
TRAINING STORMS. FOR THE ENVIRONMENT, PWATS REACH THE 95TH
PERCENTILE VALUES FOR LATE MAY WHILE CAPE 500-1000 J/KG OFFER
ENOUGH UP-SCALE GROWTH TO BETTER MAXIMIZE MOISTURE CONTENT. THEN
MID-LEVEL FLOW WILL BE SLOW (AROUND 15 KTS), WESTERLY AND
FAIRLY PARALLEL TO THE SURFACE STALLED BOUNDARY, INCREASING THE
ODDS OF TRAINING. THE COMBINATION OF PEAK FRONTOGENESIS AND
INSTABILITY FAVOR RISKS MAXIMIZING BETWEEN 9AM TO 5PM WEDNESDAY,
BUT STORMS PRIOR TO AND AFTER THESE HOURS COULD STILL LEAD TO
FLASH FLOODING.
THE BIGGEST UNKNOWN WITHIN THE WATCH AREA IS THE NORTH-SOUTH
POSITIONING OF THIS HEAVY RAIN/THUNDERSTORM AXIS. LATEST 12Z
GUIDANCE FAVORS JUST SOUTH OF I-70, A SOUTHWARD TREND FROM THE
PRIOR 00Z PROJECTION; PROBABILITIES SUGGEST THE FLUCTUATION
COULD GO AS FAR NORTH OF ALLEGHENY COUNTY/MOST OF EAST CENTRAL
OH AND AS FAR SOUTH MORE CENTRAL WV.
KEY MESSAGE 2...
THOUGH ENSEMBLE MODELS EXHIBIT SOME VARIANCE IN THE BATTLE
BETWEEN THE DRIER AND MORE SEASONABLE AIRMASS UNDERNEATH A
SOUTHEASTERN CANADIAN TROUGH VERSUS THE WARMER AND WETTER
AIRMASS SITTING IN THE SE CONUS, PROBABILITIES FAVOR THE REGION
REMAINING MORE ON THE DRY AND SEASONABLE SIDE OF THE SPECTRUM
THURSDAY THROUGH THE WEEKEND. NO IMPACTS ARE EXPECTED AT THIS
TIME.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
WIDESPREAD VFR BEGINS THE TAF PERIOD WITH CIRRUS NORTH, STRATOCU
SETTING UP ACROSS THE MIDDLE OF THE REGION AND THEN LOWERING CLOUDS
SOUTH OF MGW.
SPOTTY AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR MGW/ZZV
ALONG A SLOWLY NORTHWARD MOVING BOUNDARY. THERE MAY BE SOME BRIEF
MVFR RESTRICTIONS IN THIS ACTIVITY BUT VFR IS EXPECTED TO CONTINUE
ELSEWHERE AND FOR MUCH OF THE AFTERNOON AND EVENING AT THESE PORTS.
PRECIP CONTINUES TO SPREAD NORTH OVERNIGHT BEGINNING AS PROB30S AT
MOST PORTS BEFORE BECOMING PREVAILING. MODELS SUGGEST VFR CIGS IN
THE EARLY ACTIVITY AND THEN A QUICK DROP TO IFR CONDITIONS BEFORE
SUNRISE. THIS DROP HAS BEEN SLOWED IN THESE TAFS BUT IFR STILL SEEMS
LIKELY (>80%) FOR LARGE PORTIONS OF THE REGION SOUTH OF BVI, WHICH
FINDS ITSELF NEAR THE GRADIENT IN IFR PROBABILITIES BUT STILL SITS
NEAR 60%. FKL/DUJ MAY FIND THEMSELVES FAR ENOUGH NORTH TO PRECLUDE
ACTUAL RAIN IMPACTS. DESPITE THIS MODELS DO SEEM TO HINT AT POSSIBLE
FOG FORMATION AT DUJ TONIGHT AND THAT HAS BEEN INCLUDED IN A TEMPO
AT THIS TIME.
OUTLOOK... THE FRONT WILL KICK BACK TO THE SOUTH AND OUT OF OUR AREA
ON WEDNESDAY AFTERNOON RETURNING AREAWIDE VFR THURSDAY AND FRIDAY
UNDER HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
EVENING FOR PAZ029-031-075-076.
OH...FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
EVENING FOR OHZ057>059-068-069.
WV...FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
EVENING FOR WVZ003-004-012-021-509>514.
DISCUSSION...FRAZIER
AVIATION...AK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page