539
FXUS61 KPBZ 111749
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
149 PM EDT THU JUN 11 2026
WHAT HAS CHANGED
SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR A MAJORITY OF THE
REGION MAINLY FOR THE WIND THREAT.
KEY MESSAGES
1) POTENTIAL FOR SEVERE WEATHER EXISTS TODAY AND FRIDAY, BUT
LARGE UNCERTAINTY EXISTS IN TIMING/COVERAGE/THREATS
2) LOW PROBABILITY FLASH FLOODING CONCERNS EXISTS THROUGH FRIDAY
DUE TO WARM, MOIST ENVIRONMENT
3) ABOVE-AVERAGE TEMPERATURE WITH POTENTIAL FOR RECORD HIGH
MINIMUMS POSSIBLE THROUGH FRIDAY, PENDING STORM OUTCOMES
DISCUSSION
KEY MESSAGE 1...
THE WARM, HUMID ENVIRONMENT WILL CONTINUE INTO FRIDAY, KEEPING
CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST. ADDITIONAL
THUNDERSTORMS ARE EXPECTED FRIDAY IN ADVANCE OF A COLD FRONT AND
CROSSING UPPER TROUGH. A BRIEF PERIOD OF DRY WEATHER AND MORE
SEASONABLE TEMPERATURE WILL FOLLOW.
HIGH SBCAPE/DCAPE VALUES AND MEAGER SHEAR SHOULD SUPPORT STORMS
CAPABLE OF DAMAGING WIND GUSTS, HOWEVER, THERE IS LOOKING TO BE A
SLIGHT INCREASE IN PROBABILITY FOR LARGE HAIL. MOST OF THE AREA
IS NOW IN A SLIGHT (2/5) RISK FOR SEVERE WEATHER (MAINLY FOR WIND).
FRIDAY FEATURES A MORE WELL DEFINED MID-LEVEL SHORTWAVE AND SURFACE
FRONTAL BOUNDARY THAT OFFERS A LIFTING MECHANISM. THIS COULD RESULT
IN MORE BULLISH PRECIPITATION/SEVERE CHANCES WITH THE AFTERNOON
PASSAGE.
KEY MESSAGE 2...
DESPITE FLUCTUATIONS IN MID-LEVEL MOISTURE CONTENT, AREA PWAT
VALUES WILL REMAIN IN THE 90TH AND HIGHER PERCENTILE RANGES
THROUGH FRIDAY WHILE THERMAL PROFILES REMAIN WARM. THESE FACTORS
ALONE CREATE NON-ZERO FLASH FLOOD RISKS AS THEY FAVOR WARM-RAIN
PROCESSES THAT RESULT IN HIGHER AND MORE EFFICIENT RAINFALL
RATES. ADD IN GENERALLY WEAKER MID-LEVEL FLOW (THOUGH STORM
MOTION QUICKENS FRIDAY), THE RISK FOR FLASH FLOODING EXISTS EACH
DAY.
HOWEVER, FAIRLY DRY SURFACES DAMPENS THE LIKELIHOOD OF FLASH
FLOODING ACTUALLY DEVELOPING FOR ANY OF THESE PERIODS. THE MOST
LIKELY OUTCOME IS MINIMAL FLOODING OCCURRENCES, WITH ISSUES ONLY
DEVELOPING IN POOR-DRAINAGE LOCATIONS THAT SEE PROLONGED
1-2"/HR RATES OR AREAS THAT HAPPEN TO SEE MULTIPLE ROUNDS OF
THESE EFFICIENT RAINS IN A SHORT AMOUNT OF TIME.
KEY MESSAGE 3...
THE COMBINATION OF AREA DEW POINTS REMAINING IN THE 60S
OVERNIGHT/70S DURING THE DAY WHILE SEEING ENOUGH PERIODS OF
SUNSHINE MEANS INCREASED HEAT CONCERNS TODAY INTO FRIDAY
MORNING, WITH IMPACTS MORE ACUTELY IMPACTING HEAT-SENSITIVE
POPULATIONS WITHIN URBAN ENVIRONMENTS. A BRIEF HOUR OF HEAT
INDICES NEAR 100F CAN'T BE RULED OUT, HOWEVER, THIS IS UNLIKELY
TO BE PROLONGED ENOUGH FOR HEADLINE ISSUANCE. EVEN STILL THE
LACK OF SIGNIFICANT OVERNIGHT COOLING CAN ACT TO EXASPERATE ANY
HEAT-RELATED IMPACTS UNTIL A COOLER AIRMASS ARRIVES FRIDAY NIGHT
INTO SATURDAY MORNING.
THE BIGGEST CAVEAT TO THIS HEAT POTENTIAL IS THAT CONVECTIVE
ACTIVITY COULD ACT TO LIMIT DIURNAL HEATING (OR FURTHER LIMIT
OVERNIGHT COOLING) IF IT RESULTS IN RAIN OVER A GIVEN LOCATION
AND/OR MAINTAINS THICKER CLOUD COVER THAN ANTICIPATED.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
WEAK SURFACE CONVERGENCE ALONG A WIND/TEMPERATURE GRADIENT IN
EASTERN OH PLUS A WEAK VORTEX TRAVERSING LAKE ERIE IS PROVIDING
LIFT WITHIN THE UNSTABLE ENVIRONMENT FOR AT LEAST SCATTERED
THUNDERSTORM DEVELOPMENT THROUGH 00Z TODAY. AREAL COVERAGE AT
TAF ONSET TIME FAVORS NEAR ZZV/FKL/DUJ BEFORE MIGRATING ESE
THROUGH PIT/LBE/MGW (AMONG ALL OTHER TERMINALS) AND THEN
TAPERING OFF/EXITING EAST NEAR/AFTER 00Z. ANY THUNDERSTORM WILL
BE CAPABLE OF HEAVY RAIN REDUCING VISIBILITIES TO 2 MILES OR
LESS, GUSTY AND ERRATIC WIND, AND POTENTIAL FOR SHORT-NOTICE
STORM DEVELOPMENT IF/WHEN OUTFLOWS COLLIDE.
VFR OVERNIGHT WILL SEE INCREASING MOISTURE CONVERGENCE AHEAD OF
THE APPROACHING SHORTWAVE/SURFACE FRONT, RESULTING IN MVFR TO
LOCALLY IFR CIGS FOR MOST TERMINALS BETWEEN 07Z-15Z. THOUGH
UNLIKELY TO OCCUR, ONE COMPONENT TO MONITOR IS HOW FAR EAST A
MCS CLUSTER PERSISTS DURING THE OVERNIGHT PERIOD AS IT LEAVES
THE LOWER OH RIVER VALLEY; IF IT SUSTAINS LONGER THAN MODELED,
THUNDERSTORMS COULD REACH ZZV (OR EVEN HLG) BETWEEN 06Z-10Z.
THIS COULD IMPACT COMPONENTS LIKE CEILING RESTRICTIONS AND
FUTURE CONVECTIVE DEVELOP FOR FRIDAY.
OUTLOOK...
CONFIDENCE REMAINS LOW IN THE COVERAGE AND LOCATION ON NEW STORM
DEVELOPMENT FRIDAY ALONG/AHEAD OF A PASSING UPPER SHORTWAVE AND
SURFACE COLD FRONT. ANY THUNDERSTORM THAT DEVELOPS LIKELY FAVORS
IFR VISIBILITIES, MVFR CIGS AND BRIEF GUSTY WIND.
DRY ADVECTION AND SUBSIDENCE IN THE POST-FRONTAL ENVIRONMENT
FAVORS VFR FRIDAY EVENING INTO SATURDAY. THE NEXT PRECIPITATION
CHANCE ARRIVES WITH SHORTWAVE MOVEMENT SUNDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...RACKLEY/FRAZIER/LUPO
AVIATION...FRAZIER
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