131
FXUS61 KPBZ 261150
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
750 AM EDT THU MAR 26 2026
WHAT HAS CHANGED
PORTIONS OF OHIO HAVE BEEN PLACED IN AN ENHANCED RISK FOR
SEVERE THUNDERSTORMS THIS EVENING INTO TONIGHT, WITH AN
EXPANSION OF THE SLIGHT RISK AREA ACROSS WESTERN PA. THE
POTENTIAL FOR FLOODING HAS INCREASED, ESPECIALLY ALONG/NEAR THE
I-70 CORRIDOR NORTHWARD TO ROUGHLY ROUTE 422. A FLASH FLOOD
WATCH MAY BE NEEDED.
KEY MESSAGES
1) SHOWERS AND THUNDERSTORMS LATE TODAY AND TONIGHT ALONG A
STRONG COLD FRONT. SOME STORMS COULD BE SEVERE.
2) LOCALLY HEAVY RAINFALL COULD CAUSE FLOODING TONIGHT INTO
EARLY FRIDAY.
DISCUSSION
KEY MESSAGE 1...
PATCHY LIGHT RAIN IS POSSIBLE THROUGH THE FIRST HALF OF THE DAY
IN WARM ADVECTION. THERE IS A SLIGHT CHANCE OF A THUNDERSTORM
WITH SOME ELEVATED INSTABILITY BUILDING IN FROM THE WEST.
A COLD FRONT IS PROGGED TO BE SITUATED FROM NRN INDIANA THROUGH
SOUTHERN LAKE ERIE BY LATE AFTERNOON. SHEAR AND INSTABILITY
BUILDING AHEAD OF THE FRONT SHOULD RESULT IN SHOWERS AND
THUNDERSTORMS DEVELOPING NEAR AND AHEAD OF THE APPROACHING
FRONT. WHILE THERE ARE TIMING DIFFERENCES IN THE CAMS, THERE IS
GENERAL AGREEMENT THAT A BAND OF SHOWERS AND THUNDERSTORMS WILL
DROP SEWD ACROSS THE REGION THIS EVENING AS THE FRONT
PROGRESSES. A LOW AND MID LEVEL JET WILL RESULT IN INCREASING
SHEAR AHEAD OF THE FRONT, WITH 50-60KT FROM 0- 6KM. THERE COULD
BE A FEW CELLS OUT AHEAD OF THE MAIN LINE AS WELL. A VEERING
WIND PROFILE, AND RESULTING CURVED HODOGRAPHS, INDICATE THE
POTENTIAL FOR ROTATION IN SOME OF THESE STORMS. MUCAPE IS
PROGGED FROM 500 TO 1000 J/KG. WITH THE AMOUNT OF SHEAR ALSO IN
PLACE, THIS WILL BRING THE POTENTIAL FOR SEVERE STORMS WITH THE
LINE AS WELL. THE MAIN HAZARDS WITH THE LINE OF STORMS ARE
EXPECTED TO BE DAMAGING WINDS, THOUGH SOME LARGE HAIL AND
ISOLATED TORNADOES ARE ALSO POSSIBLE.
THE STORM PREDICTION CENTER HAS EXTENDED THE ENHANCED RISK, OR
LEVEL 3 OUT OF 5, FOR SEVERE STORMS ACROSS PORTIONS OF EASTERN
OHIO. AN EXPANSION EASTWARD TO THE SLIGHT RISK, OR LEVEL 2 OUT
OF 5, WAS MADE ACROSS WRN PA. THIS SEEMS REASONABLE WITH A MORE
FAVORABLE TIME OF ARRIVAL OF THE STORMS, MAXIMIZING THE
AVAILABLE INSTABILITY.
SHEAR AND INSTABILITY SHOULD GRADUALLY WANE BY LATE EVENING
INTO THE OVERNIGHT, AS THE FRONT GRADUALLY MOVES SOUTHEASTWARD.
THE SPEED OF THE FRONT ITSELF WILL LIKELY BE SLOW WITH THE FLOW
ALOFT NEARLY PARALLEL TO THE FRONT. EXPECT THE SEVERE POTENTIAL
TO BE SOUTH OF PIT BY MIDNIGHT, ENDING DURING THE EARLY
OVERNIGHT HOURS. RAIN AND A FEW EMBEDDED THUNDERSTORMS WILL
THEN CONTINUE, AND COULD RESULT IN A FLOOD POTENTIAL (SEE KEY
MESSAGE 2.)
KEY MESSAGE 2...
AS MENTIONED ABOVE, A SLOW PROGRESSION TO THE COLD FRONT COULD
RESULT IN MULTIPLE ROUNDS OF HEAVY RAINFALL, FROM CONVECTION
AND POST FRONTAL HEAVY RAIN. A BAND OF PWATS RANGING FROM 1.2 TO
1.5 IS EXPECTED TO PERSIST ALONG THE SLOW MOVING FRONT
OVERNIGHT. CURRENT PROBABILITIES SHOW A 50-60 PERCENT CHANCE OF
AT LEAST 1.5 INCHES OF RAIN NEAR AND ALONG THE I-70 CORRIDOR,
EXTENDING NORTHWARD TO COLUMBIANA-ALLEGHENY-WESTMORELAND
COUNTIES.
CONSIDERED A FLASH FLOOD WATCH, BUT WILL HOLD OFF AT THIS TIME
IN COORDINATION WITH SURROUNDING NWS OFFICES. WILL REVIEW THE
LATEST CAMS AND 12Z GUIDANCE FOR FURTHER EVALUATION. FLASH
FLOOD GUIDANCE IS GENERAL 1.5 TO 2 INCHES OVER 6 HOURS, WITH 1
HOURS VALUES GENERALLY 1 TO 1.5 INCHES. PROBABILISTIC GUIDANCE,
BOTH FROM NBM AND HREF, HAVE BEEN CONSISTENT IN DEPICTING THIS
HEAVY RAIN POTENTIAL. HAVE ADDED A MENTION OF HEAVY RAIN TO THE
FORECAST, AND WILL INCLUDE THIS IN THE HAZARDOUS WEATHER
OUTLOOK. STREAM/CREEKS WILL LIKELY REMAIN ELEVATED THROUGH THE
REST OF FRIDAY INTO SATURDAY DUE TO RUNOFF FROM THE EXPECTED
RAINFALL.
AVIATION /12Z THURSDAY THROUGH MONDAY/
VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE DAY BEFORE THE
ARRIVAL OF THUNDERSTORMS IN ADVANCE OF A COLD FRONT THIS
EVENING. A LINE OF STORMS IS EXPECTED TO ADVANCE SOUTH, NEARING
FKL AROUND 22Z, AND TO PIT IN THE 00-01Z TIMEFRAME. A FEW ISOLATED
THUNDERSTORMS ARE POSSIBLE IN ADVANCE OF THIS FEATURE DURING THE
LATE AFTERNOON, BUT CONFIDENCE IS TOO LOW TO INCLUDE AT THIS
TIME. HEAVY RAIN IS EXPECTED AFTER INITIAL STORM ARRIVAL,
EVENTUALLY CLEARING FROM NORTH TO SOUTH AFTER AROUND 09Z.
CIG AND VIS RESTRICTIONS ARE EXPECTED WITH THE SHOWERS AND
STORMS. WIDESPREAD MVFR SHOULD SPREAD SOUTH THROUGH THE EVENING,
WITH A BRIEF PERIOD OF IFR CEILINGS IN MORE STRATIFORM RAIN
AFTER AROUND 04Z. STORMS MAY INITIALLY BE STRONG TO SEVERE,
PRODUCING DAMAGING WINDS AND HAIL IN THE VICINITY OF TERMINALS.
CEILINGS SHOULD IMPROVE THROUGH FRIDAY MORNING BEHIND THE
EXITING RAIN, WITH VFR RETURN ANTICIPATED AREAWIDE BEFORE 18Z
FRIDAY.
OUTLOOK...
HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY FRIDAY THROUGH
SUNDAY, KEEPING GENERAL VFR IN THE FORECAST. RAIN CHANCES AND
ASSOCIATED RESTRICTIONS RETURN MONDAY INTO TUESDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...HEFFERAN/RACKLEY
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