143
FXUS61 KPBZ 030631
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
231 AM EDT SUN MAY 3 2026
WHAT HAS CHANGED
NO ADJUSTMENTS OR CHANGES WERE MADE TO THE FORECAST PACKAGE.
KEY MESSAGES
1) FROST AND FREEZE CONCERNS WILL DISSIPATE AFTER SUNRISE TODAY.
2) WEATHER PATTERN REMAINS ACTIVE THROUGH THE UPCOMING WEEK
WHILE AREA TEMPERATURE GENERALLY REMAINS BELOW SEASONAL
AVERAGES.
DISCUSSION
KEY MESSAGE 1...
EARLY MORNING CLOUD CLEARING ALONG WITH LIGHT WIND CREATES FROST
AND FREEZE RISKS FOR VEGETATION EARLY THIS MORNING AS
TEMPERATURE FALLS NEAR TO BELOW FREEZING. TEMPERATURE RISES
STARTING SHORTLY AFTER SUNRISE THAT WILL END THE FROST/FREEZE
CONCERNS (HEADLINES FAVORED TO EXPIRE AT 9AM), WITH THE REST OF
TODAY REMAINING DRY.
KEY MESSAGE 2...
THE BREAK FROM THE PREVIOUS ACTIVE AND WET PATTERN WILL BE
SHORT-LIVED AS SHOWER AND THUNDERSTORM CHANCES RETURN AS EARLY
AS MONDAY AFTERNOON/EVENING. AS WEAK IMPULSES WITHING QUASI-
ZONAL FLOW TRAVERSE THE UPPER OHIO RIVER VALLEY, A NOMINAL WARM
FRONT LIFTING NORTHWARD MAY GENERATE LATE-DAY CONVECTION THAT
FAVORS EASTERN OH BEFORE WEAKENING/DISSIPATING THROUGH TUESDAY
MORNING. LATEST MODEL TRENDS SUGGEST THIS EVENING PERIOD AS
BEING THE BEST WINDOW FOR SEVERE RISKS IN THE FORM OF DAMAGING
WIND/HAIL IN EASTERN OH, BUT THIS IS A VERY LOW PROBABILITY
PROSPECT RELIANT ON SIGNIFICANTLY STRONGER SURFACE MOISTURE
RETURNS IN SW FLOW THAT RAISES DEWPOINTS INTO THE UPPER 50S
(ROUGHLY 10% PROBABILITY OF OCCURRENCE). IN THE SCENARIO
DEWPOINTS DO REACH THE UPPER 50S AND CONVECTION INITIATES ALONG
THE BOUNDARY, ENOUGH SHEAR WITH CAPE REACHING ALMOST 1000 J/KG
COULD INTRODUCE A LOW- END HAIL AND WIND THREAT.
MID-WEEK THEN FEATURES THE GRADUAL EASTWARD PROGRESSION OF A
SURFACE COLD FRONTAL BOUNDARY AS UPPER FLOW SLOWLY TRANSITIONS
TOWARD DEEP GREAT LAKES TROUGHING BY THURSDAY, RESULTING IN
MULTIPLE ROUNDS OF VARYING RAIN INTENSITIES. ENSEMBLE MODELS
ARE TRENDING EVEN MORE PESSIMISTIC ON SEVERE CHANCES TUESDAY
AHEAD OF THE COLD FRONT AS CONFIDENCE GROWS IN A MID-LEVEL WARM
NOSE CAP TEMPERING CAPE VALUES BELOW 500 J/KG THAT VANISHES BY
WEDNESDAY MORNING IN THE POST-FRONTAL ENVIRONMENT.
THE MAIN STORY THEN IS TEMPERATURE ONCE AGAIN FALLING WELL
BELOW SEASONAL AVERAGES AND POTENTIAL RISKS OF HIGHER RAINFALL
ACCUMULATIONS ON FAIRLY SATURATED GROUNDS, THOUGH EVEN THAT IS
TRENDING IN A LESS-RISKY MANNER. LATEST PROBABILITIES FAVOR
48-HOUR TOTALS RANGING APPROXIMATELY FROM 0.5"-1.5" (25TH TO
75TH PERCENTILES) THROUGH THURSDAY MORNING; THAT RANGE AND
LONGER DURATION IS UNLIKELY TO BE AN ISSUE BEYOND RAISING AREA
RIVER HEIGHTS. BUT VARIATIONS IN THE EXACT LOCATION OF NARROW
HEAVIER RAIN BANDS DUE TO EMBEDDED JET STREAKS ENHANCING MID-
LEVEL FRONTOGENESIS MAINTAINS A NON-ZERO FLOODING RISK WHEN
ACCOUNTING FOR THE FAIRLY SATURATED GROUNDS IN THE REGION.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
SCATTERED TO BROKEN VFR STRATOCU CONTINUES EARLY THIS MORNING,
THOUGH AREAS OF CLEARING ARE NOTED JUST UPSTREAM AS A RESULT OF
BUILDING SURFACE RIDGING. DRY ADVECTION AND LINGERING CLOUD
COVER SHOULD PRECLUDE WIDESPREAD RADIATION FOG, THOUGH STEAM FOG
WILL STILL BE POSSIBLE IN THE LARGER RIVER VALLEYS. THIS SHOULD
NOT IMPACT TAF SITES.
VFR CONDITIONS CONTINUE THROUGH THE TAF PERIOD, WITH SCATTERED
TO BROKEN CUMULUS EXPECTED DURING THE AFTERNOON. WIND WILL BACK
SLIGHTLY TO WEST BY MIDDAY, WITH SOME GUSTS BETWEEN 15 AND 20
KNOTS DURING AFTERNOON MIXING. GUSTS WILL SLACKEN WITH SUNSET.
OUTLOOK...
VFR IS EXPECTED THROUGH MOST OF MONDAY UNDER HIGH PRESSURE.
RESTRICTION AND SHOWER/THUNDERSTORM POTENTIAL INCREASE LATE
MONDAY INTO TUESDAY AHEAD OF AN APPROACHING COLD FRONT. A FEW
THUNDERSTORMS ARE ALSO POSSIBLE ON TUESDAY. MORE WIDESPREAD
RESTRICTIONS IN SHOWERS ARE LIKELY TUESDAY NIGHT INTO WEDNESDAY
AS A WAVE OF LOW PRESSURE TRACKS ALONG THE COLD FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ007>009-
013>016-020>022-029-031-073>078.
OH...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR OHZ039>041-
048>050-057>059-068-069.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ001>004-012-
021-509>514.
DISCUSSION...FRAZIER
AVIATION...RACKLEY/CL
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