355
FXUS61 KPBZ 212336
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
736 PM EDT THU MAY 21 2026
WHAT HAS CHANGED
WIDESPREAD RAIN CHANCES INCREASE TOMORROW INTO SATURDAY WITH A
NEW DISTURBANCE. MODERATE TO HEAVY RAIN IS EXPECTED LATE FRIDAY
INTO EARLY SATURDAY WITH A PASSING WARM FRONT.
KEY MESSAGES
1) RAIN CHANCES REMAIN ELEVATED OVER THE MEMORIAL DAY WEEKEND
AND INTO EARLY NEXT WEEK; FLOOD CHANCES ARE LOW
2) ABOVE-AVERAGE TEMPERATURES EXPECTED NEXT WEEK
DISCUSSION
KEY MESSAGE 1...
RAIN CHANCES ACROSS THE RIDGES WILL GRADUALLY DECREASE THROUGH
THE EVENING. COOLER-THAN-AVERAGE TEMPERATURES ARE EXPECTED
TODAY DUE TO LINGER LOW-LVL MOISTURE AND PERSISTENT CLOUD
COVERAGE.
ANOTHER DISTURBANCE IS FORECAST TO DEVELOP OVER THE MISSISSIPPI
RIVER VALLEY LATE TONIGHT TONIGHT AND MOVE INTO THE OHIO RIVER
VALLEY BY FRIDAY MORNING. MODERATE TO HEAVY RAIN SHOWERS ARE
EXPECTED AS THE WARM FRONT MOVES THROUGH LATE FRIDAY INTO EARLY
SATURDAY. CURRENT HIGH-RESOLUTION MODEL GUIDANCE INDICATES THE
HEAVIEST BAND OF RAINFALL WILL LIKELY SET UP ACROSS EASTERN
OHIO, WHERE STRONGER FRONTOGENESIS IS PROJECTED. HOWEVER, IF
THE LOW-PRESSURE CENTER SHIFTS FARTHER EAST, THAT HEAVIER
RAINFALL AXIS COULD EXTEND INTO THE PITTSBURGH AREA.
THE PROBABILITY OF RAINFALL TOTALS REACHING OR EXCEEDING 1 INCH
REMAINS HIGH ACROSS EASTERN OHIO--GREATER THAN 70% THROUGH EARLY
SATURDAY MORNING. ISOLATED ROADWAY FLOODING MAY OCCUR IN
LOCALIZED LOW-LYING AREAS, ESPECIALLY NEAR CREEKS AND STREAMS
SATURDAY MORNING. ADVANCING DRY AIR IN THE WAKE OF THE WARM
FRONT SATURDAY AFTERNOON WILL LIKELY DECREASE RAINFALL
INTENSITY.
RAIN CHANCES ARE EXPECTED TO PERSIST INTO EARLY NEXT WEEK AS THE
OVERALL WEATHER PATTERN REMAINS LARGELY UNCHANGED. ADDITIONAL
DISTURBANCES ARE FORECAST TO DEVELOP ACROSS THE SOUTHEAST AND
TRACK NORTHWARD INTO THE REGION. LONG-RANGE GUIDANCE CONTINUES
TO INDICATE A LOW THREAT FOR SEVERE THUNDERSTORMS OVER THE NEXT
SEVERAL DAYS, WITH WEAK INSTABILITY AND LIMITED WIND SHEAR
EXPECTED TO KEEP SEVERE WEATHER POTENTIAL MINIMAL.
KEY MESSAGE 2...
LONG-RANGE ENSEMBLE GUIDANCE CONTINUES TO CONSISTENTLY INDICATES
THAT A RIDGE AXIS WILL STRENGTHEN OVER THE MIDWEST AND GREAT
LAKES, DRIVEN BY A STALLED LOW-PRESSURE SOUTH OF ALASKA. AS A
RESULT, ABOVE-AVERAGE TEMPERATURES ARE EXPECTED TO PERSIST, WITH
HIGHS GENERALLY REACH THE LOW TO MID-80S.
THE PROBABILITY OF REACHING "MODERATE" OR GREATER HEAT RISK---
WHICH CAN IMPACT HEAT-SENSITIVE INDIVIDUALS, PARTICULARLY THOSE
WITHOUT AIR CONDITION--IS FORECAST TO INCREASE TO AROUND
40-50%BY THE WEEKEND OF MAY 30TH.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
MVFR CEILINGS LINGER AT MGW DUE TO ITS CLOSER PROXIMITY TO A
STALLED FRONTAL BOUNDARY LOCATED OVER THE MID ATLANTIC AND
TENNESSEE VALLEY. ELSEWHERE ACROSS THE AREA, VFR CEILINGS AND
GENERALLY LIGHT EAST TO NORTHEAST FLOW PREVAILS THROUGH MUCH OF
THE NIGHT.
CEILINGS GRADUALLY LOWER THROUGHOUT THE DAY FRIDAY AS THE
STALLED FRONT LIFTS BACK NORTH AS A WARM FRONT, BRINGING
WIDESPREAD RAIN CHANCES FROM S-N AND MVFR/IFR RESTRICTIONS TO
BOTH CEILINGS AND VISIBILITIES. MEANWHILE, WINDS SHIFT TO MORE
EAST-SOUTHEASTERLY AND INCREASE TO AROUND 10 KNOTS WITH
OCCASIONAL GUSTS TO 15-20 KNOTS.
OUTLOOK...
WIDESPREAD RESTRICTIONS IN RAIN ARE EXPECTED TO CONTINUE INTO
SATURDAY WITH A CROSSING WARM FRONT. SOME IMPROVEMENT IS
POSSIBLE SUNDAY UNTIL A COLD FRONT APPROACHES LATER IN THE DAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...CERMAK
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