374
FXUS61 KPBZ 241747
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
147 PM EDT WED JUN 24 2026
WHAT HAS CHANGED
LITTLE CHANGE TO THE FORECAST OVERALL WITH SEVERE WEATHER LOOKING
MORE LIKELY TOMORROW.
KEY MESSAGES
1) ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE THURSDAY.
STALLED BOUNDARY KEEPS CHANCE OF PRECIPITATION FOR AREAS SOUTH
OF PITTSBURGH.
2) INCREASING CONFIDENCE IN THE DEVELOPMENT OF HOT AND HUMID
CONDITIONS NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
A SURFACE LOW IS FORECAST TO SWING ACROSS THE GREAT LAKES ON
THURSDAY AND INTO THE NORTHEAST CONUS BY FRIDAY MORNING. THIS WILL
PUSH A SURFACE BOUNDARY INTO THE REGION THURSDAY. DUE TO A
PREFRONTAL SURFACE TROUGH, THERE IS THE CHANCE FOR SOME EARLY
MORNING SHOWERS ACROSS NORTHWESTERN PA. THE MAIN PUSH OF SHOWERS
AND STORMS THURSDAY AFTERNOON AND EVENING WILL HAVE THE SUPPORT
OF THE CROSSING FRONT AND TROUGH AXIS. STORMS SHOULD FIRE IN A
MODERATELY FAVORABLE ENVIRONMENT, WITH HREF MEANS SUGGESTING
AROUND 500-750 J/KG OF SURFACE-BASED CAPE AND 40-45 KNOTS OF
0-6KM SHEAR. IT IS STILL NOT CLEAR WHETHER THIS WILL BE A LINE
OF THUNDERSTORMS OR INDIVIDUAL STORMS THAT POP-UP ALONG THE
BOUNDARY. SEVERE WEATHER SEEMS A POSSIBILITY, WITH THE PRIMARY
THREAT BEING DAMAGING WIND GUSTS AND HAIL AS A SECONDARY THREAT.
THERE CONTINUE TO BE SIGNS THAT THE BOUNDARY MAY STALL SOMEWHERE IN
THE OHIO VALLEY BY FRIDAY AND INTO THE WEEKEND, AS IT ALIGNS WITH
QUASI-ZONAL MID-LEVEL FLOW. THIS WILL KEEP PRECIPITATION CHANCES
CONTINUING INTO FRIDAY AND SATURDAY MAINLY FOR AREAS SOUTH OF
PITTSBURGH. GIVEN THE POSSIBILITY OF REPEATED ROUNDS OF SHOWERS AND
THUNDERSTORMS, RAINFALL TOTALS IN THESE AREAS WILL NEED TO BE
MONITORED INTO SATURDAY. PRECIPITABLE WATER VALUES IN THIS REGION
GENERALLY PEAK IN THE 90TH PERCENTILE FRIDAY NIGHT INTO SATURDAY
WHICH IS ENOUGH TO FUEL HEAVY RAIN TOTALS IN TRAINING SITUATIONS,
WHICH COULD OCCUR WITH A QUASI-STATIONARY BOUNDARY IN THE AREA FOR A
TIME.
KEY MESSAGE 2...
THE BOUNDARY IS FORECAST TO MOVE SOUTH ON SUNDAY AS A HIGH MOVES IN
BEHIND IT. THERE IS BROAD ENSEMBLE AGREEMENT OF AN IMPRESSIVE 500MB
RIDGE BUILDING ACROSS THE LOWER MISSISSIPPI AND OHIO RIVER VALLEYS
BY EARLY NEXT WEEK. THERE IS A HIGH PROBABILITY OF 500MB HEIGHTS
RISING ABOVE THE 590DM LEVEL BY NEXT MONDAY. THIS WOULD LIKELY
SUPPRESS ANYTHING MORE THAN ISOLATED AFTERNOON CONVECTION EARLY NEXT
WEEK. THE MAIN IMPACT IN THIS PATTERN WOULD BE THE INCREASINGLY HOT
AND HUMID CONDITIONS WHICH COULD DEVELOP, WITH TEMPERATURES IN THE
90S LOOKING INCREASINGLY LIKELY TO END THE MONTH OF JUNE.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
HIGH CONFIDENCE VFR WEATHER THROUGH THE TAF PERIOD. SCATTERED CU
IS EXPECTED THROUGH THE AFTERNOON, BUT SHOULD COLLAPSE WITH
SUNSET. TONIGHT, INCREASING HIGH CLOUDS ARE EXPECTED WITH
SOUTHWESTERLY FLOW ALOFT. SURFACE WIND WILL REMAIN LESS THAN 10
KNOTS THROUGH THE PERIOD.
SHOWER AND THUNDERSTORM CHANCES WILL INCREASE AFTER 18Z
THURSDAY, WITH SOME UNCERTAINTY IN INITIATION TIME (MID VS LATE
AFTERNOON). FOR NOW COVERED THIS WITH PROB30S. STRONG STORMS
ARE POSSIBLE, MAINLY PRODUCING DAMAGING WIND GUSTS.
OUTLOOK...
PERIODIC SHOWER AND THUNDERSTORM CHANCES AND RELATED
RESTRICTIONS WILL CONTINUE THROUGH THE WEEKEND AS A FRONT STALLS
TO OUR SOUTH. HIGHEST CHANCES WILL REMAIN SOUTH OF PITTSBURGH.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL/LUPO
AVIATION...RACKLEY/FRAZIER
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