347
FXUS61 KPBZ 090609
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
209 AM EDT WED SEP 9 2026
WHAT HAS CHANGED
UPDATE TO AVIATION DISCUSSION
KEY MESSAGES
1) A PASSING TROUGH AND COLD FRONT LATE WEDNESDAY INTO THURSDAY
WILL RETURN SHOWERS AND THUNDERSTORMS TO THE REGION.
2) AN ACTIVE WEATHER PATTERN COULD OCCUR EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
CONFIDENCE REMAINS HIGH THAT QUIET AND DRY WEATHER WILL PERSIST
THROUGH WEDNESDAY AFTERNOON UNDER HIGH PRESSURE. TEMPERATURES
WILL TREND ABOVE AVERAGE THROUGH TOMORROW WITH SOUTHERLY WINDS
AHEAD OF AN APPROACHING DISTURBANCE.
MODELS CONTINUE TO DEPICT A LARGE-SCALE TROUGH TRACKING OVER THE
GREAT LAKES EARLY WEDNESDAY INTO THURSDAY. THIS SYSTEM WILL
WEAKEN THE RIDGE OVER THE CENTRAL CONUS AS IT MOVES EASTWARD
OFFSHORE THE MID-ATLANTIC COASTLINE. THIS WILL ALLOW FOR MORE
ACTIVE WEATHER TO DEVELOP ACROSS THE REGION.
WITH THE LOW-LEVEL MOISTURE ADVECTION (DEW POINTS CLIMBING INTO
THE UPPER-60S/LOW-70S) AND SURFACE TEMPERATURES IN THE MID TO
UPPER-80S, HEAT INDEX VALUES COULD APPROACH 90 DEGREES BY LATE
WEDNESDAY AFTERNOON IN A FEW AREAS AND CAUSE HEAT STRESS TO
LOCAL COMMUNITIES. PARTS OF EASTERN OHIO COULD HAVE A 30%-50%
FOR HEAT INDICES TO EXCEED 90 DEGREES.
BETWEEN 7PM TO 9PM WEDNESDAY, PRECIPITATION CHANCES WILL
INCREASE JUST SOUTH OF LAKE ERIE WITH AN APPROACHING TROUGH
FOLLOWED BY A COLD FRONT. THIS WILL MOVE SOUTHEASTWARD OVERNIGHT
AND BE INTO NORTHERN WV BY THURSDAY MORNING. THE PROBABILITY OF
STRONG TO SEVERE STORMS ROSE TO 15%-29% FOR PARTS OF
NORTHWESTERN PA AND EASTERN OHIO WHERE THE GREATEST PROBABILITY
FOR 750 J/KG OF CAPE AND 30KTS OF SHEAR WILL BE ALONG WITH
NOTABLE CURVATURE IN 0-3KM HODOGRAPHS. THE MAIN THREAT WITH
THESE STORMS WILL BE WIND, THOUGH AN ISOLATED TORNADO COULD
DEVELOP IN STORMS WITH A SUBTLE RIGHT VEER FROM STORM MOTION.
SUNSET APPEARS TO SIGNIFICANTLY REDUCE THE INSTABILITY THUS
REDUCING THE CHANCE FOR SOUTHWESTERN PA AND NORTHERN WV TO
EXPERIENCE SEVERE WEATHER.
THE PROLONGED PASSAGE OF THE TROUGH MAY SUPPORT PERIODS OF
MODERATE TO HEAVY RAINFALL TOTALS ON THURSDAY, POTENTIALLY
RESULTING IN ISOLATED FLOODING NEAR CREEKS AND STREAMS. SOME
AREAS COULD RECEIVE 1 TO 1.5 INCHES OF RAINFALL DURING THIS
PERIOD. CURRENTLY, THERE IS LOW CONFIDENCE WITH MODELS NOT
AGREEING ON THE LOCATION OF THE HEAVIEST PRECIPITATION WITH SOME
SHOWING AN AREA FROM SOUTHERN OHIO EXTENDING NORTHEASTWARD INTO
CENTRAL PA WHILE OTHERS FOCUSING MORE OVER WESTERN OHIO AND
SOUTHERN INDIANA.
KEY MESSAGE 2...
MACHINE-LEARNING MODELS SUGGEST THAT AFTER A BRIEF PERIOD OF
RIDGING, FRIDAY THROUGH SATURDAY, OUR LARGE-SCALE WEATHER
PATTERN WILL TRANSITION TO A MORE ZONAL FLOW. AS A RESULT, THIS
WILL ALLOW DISTURBANCES FORMING UPSTREAM (NEAR THE ROCKIES) TO
TRACK INTO OUR AREA. THIS PATTERN COULD CREATE A HEAVY RAIN
THREAT AND/OR A SEVERE WEATHER THREAT EARLY NEXT WEEK AND WILL
NEED TO BE MONITORED.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
VFR IS EXPECTED THROUGH MUCH OF WEDNESDAY UNDER HIGH PRESSURE.
THE CU RULE AND MODEL SOUNDINGS INDICATE A SCATTERED DIURNAL
CUMULUS LAYER SHOULD DEVELOP ON WEDNESDAY, WITH CONTINUED CIRRUS
ABOVE. A FEW STRAY SHOWERS CAN'T BE RULED IN THE VICINITY OF
TERMINALS BETWEEN 15Z TO 23Z.
A PASSING TROUGH AND ITS ASSOCIATED COLD FRONT WILL BEGIN TO
APPROACH FROM THE NW LATE TODAY, MAINLY AFTER 23Z. AN INCREASING
PRESSURE GRADIENT AND MIXING AHEAD OF THE FRONT SHOULD RESULT
IN GUSTY SW WIND ON WEDNESDAY AS WELL.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP SOUTH OF LAKE
ERIE BETWEEN 22Z TO 00Z AND ADVANCE SOUTH INTO EARLY THURSDAY
MORNING. TEMPOS HAVE BEEN ADDED BASED ON HIGH RESOLUTION MODEL
DATA TIMING.
OUTLOOK...
RESTRICTIONS, MVFR TO IFR CIGS, COULD CONTINUE INTO EARLY
THURSDAY MORNING DUE TO LINGERING LOW-LEVEL MOISTURE.
VFR SHOULD RETURN FRIDAY BEFORE ANOTHER SHORTWAVE TROUGH
RETURNS SHOWER CHANCES SATURDAY AND SUNDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN/LUPO
AVIATION...WM/HEFFERAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page