945
FXUS61 KPBZ 260559
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
159 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 /06Z THURSDAY THROUGH MONDAY/
EXPECT VFR CONDITIONS TO PERSIST FOR A LARGE PORTION OF THE DAY
BEFORE A COLD FRONT ADVANCES BETWEEN 22Z TO 02Z TONIGHT.
BEFORE SUNRISE, LLWS FROM THE SOUTHWEST IS EXPECTED WITH A
PASSING JET OVER THE GREAT LAKES AND INTO THE NEW YORK AREA.
BETWEEN 12Z AND 15Z SFC WIND GUSTS WILL INCREASE WITH DIURNAL
HEATING.
CIGS AND VIS RESTRICTIONS, ASSOCIATED WITH SHOWERS AND STORMS,
ARE EXPECTED TO EXPAND IN COVERAGE FROM NORTH TO SOUTH (STARTING
WITH DUJ/FKL) AFTER 23Z AND CONTINUE INTO EARLY FRIDAY MORNING.
A FEW OF THESE STORMS COULD BE CONSIDERED STRONG TO SEVERE,
PRODUCING HAIL AND DAMAGING WINDS IN THE VICINITY OF THE
TERMINALS.
WITH THE SLOW PROGRESSION OF THE FRONT AND ASSOCIATED TROUGH,
RAIN CHANCES WILL REMAIN ELEVATED THROUGH 12Z FOR ALL TERMINALS.
BETWEEN 15Z TO 17Z FRIDAY, HIGH RESOLUTION MODELS DEPICT THE
COLD FRONT SOUTH OF MGW AND PRECIP CHANCES DECREASING FROM NORTH
TO SOUTH THROUGHOUT THE LATE MORNING.
CIGS WILL LIKELY RISE TO MVFR AND THEN VFR BETWEEN 17Z AND 21Z
FRIDAY WITH WINDS DIRECTED FROM THE NORTH.
OUTLOOK...
VFR SHOULD THEN CONTINUE THROUGH SUNDAY AS SURFACE HIGH
PRESSURE BUILDS ACROSS THE OH VALLEY AND MID ATLANTIC REGION.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM
AVIATION...HEFFERAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page