875
FXUS61 KPBZ 210932
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
532 AM EDT SAT MAR 21 2026
WHAT HAS CHANGED
SPC HAS ADJUSTED THE THE SLIGHT RISK (LEVEL 2 OF 5) AND MARGINAL
RISK (LEVEL 1 OF 5) SOUTH. THERE STILL REMAINS SOME UNCERTAINTY OF
THE POSITION/TIMING OF THE FRONT WHICH COULD IMPACT WHEN AND WHERE
SEVERE WEATHER WILL IMPACT.
KEY MESSAGES
1) STORM POTENTIAL ON SUNDAY WITH PASSING COLD FRONT, ALL
SEVERE THREATS IN PLAY.
DISCUSSION
KEY MESSAGE 1...
AFTER A QUIET SATURDAY, A SOMEWHAT ROBUST THREAT FOR SEVERE
WEATHER IS PRESENT FOR SUNDAY. WARM FRONTAL PASSAGE SATURDAY
NIGHT, ATTACHED TO GREAT LAKES LOW PRESSURE, ALLOWS FOR
SOUTHWEST FLOW PROMOTING STRONG HEATING DURING THE SUNDAY
DAYLIGHT HOURS. WELL-ABOVE NORMAL HIGH TEMPERATURES ARE
FORECAST, SUPPORTED BY 850MB TEMPERATURES APPROACHING 15C. HIGHS
WILL MAINLY BE IN THE 70S, PERHAPS NEAR 80 IN THE VICINITY OF
THE MASON-DIXON LINE.
ONE OF THE PARAMETERS WE LOOK AT FOR SEVERE WEATHER IS EFFECTIVE
BULK WIND DIFFERENCE (EBWD) WHICH MEASURES THE VERTICAL WIND SHEAR
WITHIN A STORM. DURING SUNDAY AFTERNOON/EVENING, FORECAST SOUNDINGS
ARE INDICATING AN EBWD OF 45-60 KTS WHICH IS FAVORABLE FOR SUPERCELL
DEVELOPMENT. THE ENSEMBLES MUCAPE (MOST-UNSTABLE CAPE), A SEVERE
WEATHER PARAMETER THAT CAN GIVE US AN INDICATION OF INSTABILITY, IS
AT LEAST 500-1000 J/KG SUNDAY AFTERNOON MAINLY FOR AREAS AROUND
PITTSBURGH AND SOUTH. AS THE COLD FRONT DROPS ACROSS THE REGION
DURING THE AFTERNOON/EVENING AND INTERACTS WITH THIS ENVIRONMENT,
SOME SUPERCELL STRUCTURES MAY DEVELOP WITH ALL SEVERE HAZARDS ON THE
TABLE.
AT PRESENT, PARAMETERS APPEAR BEST ALIGNED IN EASTERN OHIO,
SOUTHWESTERN PENNSYLVANIA, AND NORTHERN HALF OF WEST VIRGINIA. THERE
STILL REMAINS SOME UNCERTAINTY OF THE POSITION/TIMING OF THE FRONT
WHICH COULD IMPACT WHEN AND WHERE SEVERE WEATHER WILL IMPACT.
WEAKENING CONVECTION WOULD ACCOMPANY THE FRONT THROUGH THE NIGHT,
WITH DRY WEATHER AND COOLER TEMPERATURES RETURNING FOR MONDAY.MONDAY.
AVIATION /09Z SATURDAY THROUGH WEDNESDAY/
WITH A PASSING COLD FRONT, CIGS WILL CONTINUE TO DECREASE FROM
NORTH TO SOUTH DUE TO RESIDUAL LOW-LEVEL MOISTURE FROM PRECIP
OVER THE LAST 24 HOURS. CIGS WILL LIKELY RANGE FROM MVFR TO IFR
FROM 06Z TO 12Z EARLY THIS MORNING.
HI-RES GUIDANCE SUGGEST CIGS TO IMPROVE TO VFR BETWEEN 14Z TO
16Z TODAY WITH SFC HEATING AFTER DAY BREAK. WINDS WILL SHIFT
FROM THE SOUTH THROUGHOUT THE DAY.
OUTLOOK...
A NEW COLD FRONT COULD RETURN STRONG TO SEVERE THUNDERSTORMS
SUNDAY AFTERNOON AND EVENING. RESTRICTIONS WILL LIKELY LINGER
INTO MONDAY MORNING BEFORE VFR RETURNS MONDAY AFTERNOON.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL/LUPO
AVIATION...HEFFERAN
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