261
FXUS61 KPBZ 210600
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
200 AM EDT THU MAY 21 2026
WHAT HAS CHANGED
NO MAJOR CHANGES WERE MADE TO THE FORECAST. PERIODIC RAIN AND
POSSIBLE THUNDERSTORMS EXPECTED FRIDAY AND SATURDAY. MORE
INTERMITTENT SHOWERS/POSSIBLE THUNDERSTORMS SUNDAY AND MONDAY.
KEY MESSAGES
1) RAIN CHANCES DECREASE FROM N-S TODAY
2) ROUNDS OF RAIN AND POSSIBLE THUNDERSTORMS LATER FRIDAY INTO EARLY
NEXT WEEK. LOCALLY HEAVY RAINFALL POSSIBLE ESPECIALLY FRIDAY NIGHT
INTO SATURDAY NIGHT. GUSTY DOWNSLOPE WIND ALSO POSSIBLE FRIDAY AND
SATURDAY.
DISCUSSION
KEY MESSAGE 1...
A COLD FRONT WAS LOCATED FROM THE MID ATLANTIC TO THE LOWER
OHIO VALLEY. A SHORTWAVE TRACKING ALONG THE NORTHERN SIDE OF
THE FRONT WILL CONTINUE TO BRING RAIN TO AREAS SOUTH OF I-80
EARLY THIS MORNING, THOUGH THESE CHANCES WILL DECREASE FROM N-S
AS THE WAVE GRADUALLY EXITS AND THE FRONT DROPS SLOWLY SOUTH.
AREAS SOUTH OF THE I-68 CORRIDOR WILL BE THE LAST TO SEE THE
RAIN END LATE TODAY. HIGHS ARE EXPECTED TO BE 5 TO 10 DEGREES
BELOW AVERAGE.
KEY MESSAGE 2...
A TROUGH IS EXPECTED TO ADVANCE EASTWARD FROM THE CENTRAL CONUS
ON FRIDAY. INCREASING MOISTURE AND ASCENT IN WARM ADVECTION IN
SOUTHWEST FLOW AHEAD OF THE TROUGH, AND A SURFACE WARM FRONT
LIFTING NORTHWARD, WILL RESULT IN RAIN CHANCES INCREASING FROM
S-N FRIDAY. WIDESPREAD RAIN IS EXPECTED FRIDAY NIGHT INTO
SATURDAY AS THE WARM FRONT CONTINUES LIFTING NORTH ACROSS THE
REGION. PRECIPITABLE WATER IS PROGGED TO INCREASE TO BETWEEN
1.5 AND 1.75 BY SATURDAY MORNING, WITH CONTINUED WARM, MOIST
ADVECTION. THERE IS SOME INDICATION OF VERY LIMITED ELEVATED
INSTABILITY, WITH THE THUNDER POTENTIAL LOW. THE WARM FRONT
SHOULD BE NORTH OF THE REGION BY SATURDAY NIGHT, WITH SHOWERS
AND POSSIBLE THUNDERSTORMS AS THE UPPER TROUGH AXIS CROSSES THE
REGION. CURRENT NBM PROBABILITIES INDICATE A 60-80 PERCENT
CHANCE OF AT LEAST ONE INCH OF RAIN FROM FRIDAY THROUGH EARLY
SUNDAY MORNING, WITH A 30-50 PERCENT CHANCE OF 2 INCHES.
PROBABILITIES ARE LOWER ON THE LEE SIDE OF THE RIDGES, WHERE
SOME LOW LEVEL DOWNSLOPING IS LIKELY. LOCALIZED FLOODING WILL
BE POSSIBLE IN FLOOD PRONE AREAS, AND WHERE HEAVIER RAIN
PERSISTS.
THE DOWNSLOPING SHOULD RESULT IN GUSTY SE WIND ESPECIALLY ON
THE LEE SIDE OF THE LAUREL HIGHLAND RIDGES, DEVELOPING FRIDAY
AND CONTINUING SATURDAY. AT THIS TIME, IT LOOKS AS THOUGH
INVERSION HEIGHTS SHOULD KEEP GUSTS IN THE 30-35 KT RANGE,
THOUGH THESE GUSTS COULD BE PERSISTENT THROUGH THIS PERIOD.
GUSTS SHOULD DIMINISH SATURDAY NIGHT AS THE FLOW VEERS TO THE
SOUTH AND LOW LEVEL WIND DIMINISHES.
WHILE SHOWER AND THUNDERSTORM CHANCES CONTINUE SUNDAY, THEY
SHOULD BE MORE LIMITED AND NOT AN ALL DAY RAIN WITH THE AREA IN
BETWEEN THE EXITING SHORTWAVE IN THE MORNING, AND AN
APPROACHING SHORTWAVE ACROSS THE MIDWEST. THE MIDWESTERN
SHORTWAVE/SURFACE TROUGH SHOULD TRACK ACROSS THE REGION SUNDAY
NIGHT, WITH HIGHER SHOWER/STORM CHANCES. MORE UNCERTAINTY
EXISTS FOR MONDAY. PRECIP CHANCES WILL DEPEND ON WHERE THE
SURFACE TROUGH STALLS ACROSS THE LOWER OHIO VALLEY REGION.
MAINTAINED THE NBM POPS WITH A VARIETY OF MODEL ENSEMBLE
SOLUTIONS AND UNCERTAINTY.
ENSEMBLE RIVER FORECASTS INDICATE ELEVATED RIVER LEVELS ARE
LIKELY BEGINNING OVER THE WEEKEND INTO NEXT WEEK.
AVIATION /06Z THURSDAY THROUGH MONDAY/
POST-FRONTAL LIGHT RAIN CONTINUES ACROSS THE REGION AS OF 06Z;
THIS WILL SLOWLY SHIFT SOUTH AND EAST THROUGH THE MORNING AS A
DRIER AIR MASS SETTLES IN FROM THE NORTH. CEILINGS FROM PIT ON
NORTH HAVE ACHIEVED VFR AND SHOULD REMAIN THERE FOR THE TAF
PERIOD, WITH CLOUD BASE HEIGHTS SLOWLY LIFTING WITH TIME.
TO THE SOUTH, MVFR CEILINGS LINGER AT HLG, LBE, AND ZZV, WHILE
IFR DOMINATES AT MGW. THE FRONT WHICH CROSSED YESTERDAY IS
FORECAST TO STALL ACROSS CENTRAL OR NORTHERN WV, THESE CEILINGS
TO CONTINUE INTO THURSDAY. IMPROVEMENT TO VFR IS MOST LIKELY AT
HLG BY LATE THURSDAY MORNING, BUT LBE AND MGW MAY SEE
RESTRICTIONS REMAIN UNTIL LATER IN THE DAY, AND MGW MAY NOT
ACHIEVE VFR AT ALL THROUGH 06Z FRIDAY. WIND AROUND 10 KNOTS WILL
SLOWLY VEER FROM NORTH TO EAST WITH TIME.
OUTLOOK...
ALL TERMINALS MAY REACH VFR STATUS BY MID-MORNING FRIDAY.
HOWEVER, WIDESPREAD RESTRICTIONS IN RAIN ARE EXPECTED TO
OVERSPREAD THE REGION FROM S-N FRIDAY AFTERNOON INTO SATURDAY
WITH A 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...WM
AVIATION...CL
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