462
FXUS61 KPBZ 110750 AAA
AFDPBZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
350 AM EDT WED MAR 11 2026
WHAT HAS CHANGED
LITTLE CHANGE IN THE OVERALL SEVERE THREAT FOR TODAY. EARLY
MORNING CONVECTION IS INCREASINGLY UNLIKELY, WITH TWO ROUNDS OF
MID/LATE MORNING AND MID AFTERNOON THUNDERSTORMS THE GREATEST
THREAT FOR SEVERE WEATHER (PRIMARILY DAMAGING WIND AND
TORNADOES). SOME UNCERTAINTY REMAINS WITH COLD FRONTAL
CONVECTION, BUT INDICATIONS POINT TO A WEAKER, LESS-ORGANIZED
LINE.
KEY MESSAGES
1) WIDESPREAD RAIN AND SEVERE THUNDERSTORM CHANCES TODAY
2) WINDY AND COOLER LATE WEEK WITH RAIN/SNOW CHANCES
DISCUSSION
KEY MESSAGE 1...
SURFACE LOW PRESSURE WILL DEEPEN AND CROSS THE GREAT LAKES
TODAY. BROAD ASCENT UNDER DIFFLUENT MID-LEVEL FLOW WITH WARM
AND MOIST ADVECTION SHOULD SUPPORT SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS BEFORE A COLD FRONT PASSES THIS EVENING. SEVERE
THUNDERSTORMS, CAPABLE OF PRODUCING STRONG DAMAGING WIND GUSTS,
TORNADOES, AND HAIL, WILL BE MOST LIKELY DURING THE LATE MORNING
AND AFTERNOON ROUNDS OF CONVECTION. CONFIDENCE IN SEVERE STORMS
ALONG/JUST AHEAD OF THE COLD FRONT IS LOWER.
THIS MORNING FINDS US ALREADY IN THE OPEN WARM SECTOR WITH THE
NEAREST LEADING CONVECTION ACROSS NORTHERN INDIANA, NW OHIO,
AND INTO SOUTHERN ONTARIO. CAMS DO STILL GENERALLY SHOW A FEW
SHOWERS/THUNDERSTORMS DEVELOPING NEAR DAYBREAK OVER OHIO AND
CROSSING INTO WESTERN PA, BUT COVERAGE AND INTENSITY OF THIS
CONVECTION IS FAR LESS THAN PREVIOUSLY ADVERTISED. MORE
SIGNIFICANT CONVECTION REMAINS NORTH OF OUR FORECAST AREA.
REGARDLESS, ANY THUNDERSTORMS THIS EARLY ARE LIKELY TO REMAIN
ELEVATED GIVEN THE STABLE NEAR-SURFACE PROFILES. THIS WILL
SIGNIFICANTLY THROTTLE WIND AND TORNADO POTENTIAL, AND LACKING
MID-LEVEL THERMODYNAMICS WILL LIMIT HAIL.
IT APPEARS THE FIRST MAJOR ROUND OF CONVECTION DOES NOT ARRIVE
IN EASTERN OHIO UNTIL MID-MORNING, CROSSING THE PITTSBURGH
METRO AREA CLOSER TO NOON. BY THIS POINT, AN 850-700 MB LOW
LEVEL JET WILL HAVE RAMPED UP WITH CONVECTIVE COVERAGE ON ITS
NOSE. MLCAPE VALUES ARE PROGGED TO AROUND 500 J/KG, HODOGRAPHS
ELONGATE, AND HREF MEAN 0-1 KM SRH EXCEEDS 200 M2/S2. THIS
INDICATES A RIPE, BUT CONDITIONAL, ENVIRONMENT FOR ROTATING
STORMS. BY THIS POINT, MOST CAMS PAINT LITTLE NEAR-SURFACE
UPDRAFT HELICITY TRACKS, BUT THIS COULD BE MISLEADING AS
PROFILES LOOK MORE ISOTHERMAL OR WEAKLY UNSTABLE RATHER THAN
STABLE. WITH STRONG KINEMATICS AND LOW LCLS WITH REINFORCED
SURFACE MOISTURE, IT'S CERTAINLY PLAUSIBLE THAT THOSE ARE ENOUGH
TO OVERCOME MARGINAL THERMODYNAMIC PROFILES AND THIS ROUND
POSES A WIND AND TORNADO THREAT, CONDITIONAL ON STORMS BEING
TRULY ROOTED AT THE SURFACE.
UNCERTAINTY INCREASES HEADING INTO MID/LATE AFTERNOON. CAMS
MODEL TWO DISTINCT SCENARIOS. THE FAVORED AND INCREASINGLY
PROBABLE SCENARIO -- DEPICTED BY A MAJORITY OF CAMS -- DRIVES A
SECOND CLUSTER OF THUNDERSTORMS THROUGH THE AREA BY MID-
AFTERNOON, TRAILING THE MORNING ROUND BY ROUGHLY 2-3 HOURS. THE
CRITICAL QUESTION THEN BECOMES WHETHER THE ENVIRONMENT CAN
ADEQUATELY RECOVER TO SUPPORT A SECOND ROUND OF ORGANIZED SEVERE
CONVECTION. MODELED CAPE VALUES RECOVERING ABOVE 1000 J/KG OFFER
SOME OPTIMISM, THOUGH LINGERING CLOUD DEBRIS AND A COMPRESSED
RECOVERY WINDOW INTRODUCE CONSIDERABLE UNCERTAINTY. STORM MODE
FOR THIS ROUND TRENDS MIXED, WITH CAMS DEPICTING A COMBINATION
OF CLUSTERED/LINEAR FEATURES ALONGSIDE DISCRETE CELLS. THIS
WOULD POSE THE GREATEST TORNADO AND DAMAGING WIND POTENTIAL
GIVEN SUFFICIENT RECOVERY. THE MINORITY SCENARIO, OFFERED BY THE
3K NAM AND A FEW NSSL MPAS CAMS, CLEARS THE AREA OF CONVECTION
NEAR MIDDAY AHEAD OF THE COLD FRONTAL PASSAGE THIS EVENING.
PEAK FORCING ARRIVES WITH THE COLD FRONT THIS EVENING. THE
MINORITY SCENARIO WOULD AFFORD AMPLE RECOVERY TIME AHEAD OF
FRONTAL CONVECTION, YIELDING A STRONG QLCS WITH DAMAGING WINDS
AND AN EMBEDDED TORNADO THROUGH THE EARLY EVENING. THOUGH THIS
WOULD REPRESENT THE GREATEST SEVERE THREAT FOR THE DAY, AND
POSSIBLY PROMPT AN UPGRADE TO ENHANCED, THIS SOLUTION REMAINS
INCREASINGLY UNLIKELY. THE MORE PROBABLE OUTCOME WITH MID-
AFTERNOON CONVECTION LEAVES LITTLE OPPORTUNITY FOR ENVIRONMENTAL
RECOVERY DESPITE CONTINUED SOUTH-SOUTHWESTERLY FLOW. IN THIS
SCENARIO, FRONTAL CONVECTION ORGANIZES INTO A WEAKER, LESS-
ORGANIZED LINE WITH A MORE LIMITED SEVERE THREAT. GIVEN THE
LINGERING UNCERTAINTY, THE SLIGHT RISK HAS BEEN MAINTAINED.
KEY MESSAGE 2...
THE AFOREMENTIONED COLD FRONT WILL USHER IN A MUCH COOLER AND DRIER
AIRMASS IN ITS WAKE WITH DEW POINTS CRASHING INTO THE TEENS AND 20S
BY THURSDAY AFTERNOON. STRONG COLD ADVECTION WILL PROVIDE AN
OPPORTUNITY FOR SOME LIGHT SNOW SHOWERS IN THE AFTERNOON AS WELL,
BUT ACCUMULATION SHOULD BE MINIMAL AT BEST WITH GROUND TEMPERATURES
NEEDING A BIT OF TIME TO REACT. IN THE RIDGES WITH PERSISTENT
UPSLOPE FLOW, CAN'T RULE OUT A FEW TENTHS OF AN INCH. STEEPENED
LAPSE RATES AND MIXING WILL PROVIDE GUSTS TO 25-30 MPH.
FRIDAY LOOKS TO BE THE WINDIEST DAY AS LOW PRESSURE CROSSES OFF TO
OUR NORTH. THE BEST FORCING LOOKS TO BE IN THAT DIRECTION AS WELL,
BUT IF THE LOW NUDGES A BIT FARTHER SOUTH, WARM ADVECTION WILL DRIVE
SOME LIGHT SNOW SHOWERS PRIMARILY NORTH OF PITTSBURGH. NBM 90TH
PERCENTILE ONLY SUGGESTS AROUND AN INCH AT THE WORST CASE SCENARIO.
STRONG WIND GUSTS ARE LIKELY TO BE MOST IMPACTFUL ON FRIDAY WITH A
TIGHTENING GRADIENT. NBM PROBABILITY OF WIND ADVISORY CRITERIA (46+
MPH GUSTS) RANGE FROM ABOUT 50-70% FOR A LARGE PORTION OF THE
REGION. EASTERN TUCKER COUNTY SHOWS SIMILAR PROBABILITY TO REACH
HIGH WIND WARNING CRITERIA (58+ MPH), SO WIND HEADLINES MAY BE
NEEDED.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
WITH THE REGION WELL WITHIN THE WARM SECTOR, WARM MOIST
ADVECTION WILL PROMOTE SHOWER AND STORM DEVELOPMENT THIS MORNING
AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. LATEST
ENSEMBLES SHOW 80-100% PROBABILITIES FOR MVFR CONDITIONS
AREAWIDE DURING THE DAY AND A 50-70% CHANCE OF IFR SPREADING
FROM NORTH TO SOUTH THIS LATER THIS AFTERNOON AND THIS EVENING
ACROSS THE REGION.
THERE WILL BE SEVERE POTENTIAL WITH STORMS, ESPECIALLY FROM
MID-AFTERNOON THROUGH MID-EVENING. MUCH WILL DEPEND ON EARLIER
CONVECTION, SO EXPECT AMENDMENTS TO ADDRESS TIMING/CONDITIONS
AT MOST PORTS THROUGH THE DAY. THE MAIN IMPACT IS EXPECTED TO
BE DAMAGING WINDS, BUT LARGE HAIL AND TORNADOES CANNOT BE RULED
OUT EITHER.
SEVERAL ROUNDS OF CONVECTION WILL BE POSSIBLE, AND HAVE
HIGHLIGHTED THIS IN LATEST TAFS WITH PROB30S FOR NOW GIVEN THE
TIMING UNCERTAINTY.
WINDS ARE EXPECTED TO RAMP UP THROUGH THE DAY WITH WSW WINDS
GUSTING UP TO 30 KNOTS IN SOME INSTANCES.
OUTLOOK...
RAIN WILL TRANSITION TO SNOW LATE TONIGHT INTO THURSDAY BEHIND
THE FRONT.
CIG RESTRICTIONS AND GUSTY WIND ARE LIKELY THURSDAY IN COLD NW
FLOW AND WITH A CROSSING UPPER TROUGH. RESTRICTIONS, GUSTY WIND,
RAIN AND SNOW ARE LIKELY TO CONTINUE FRIDAY WITH ANOTHER
CROSSING COLD FRONT. VFR RETURNS SATURDAY UNDER HIGH PRESSURE.
RESTRICTIONS ARE POSSIBLE SUNDAY WITH A CROSSING WARM FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...RACKLEY/MLB
AVIATION...88
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