738
FXUS61 KPBZ 240610
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
210 AM EDT WED JUN 24 2026
WHAT HAS CHANGED
LITTLE CHANGE TO THE FORECAST OVERALL, AS CONFIDENCE IN THE
SEQUENCE OF EVENTS OVER THE NEXT SEVEN DAYS INCREASES. IN
PARTICULAR, THE DEVELOPMENT OF HOT AND HUMID CONDITIONS EARLY
NEXT WEEK SEEMS INCREASINGLY LIKELY.
KEY MESSAGES
1) DRY CONDITIONS AND SEASONABLE DAYTIME TEMPERATURES THROUGH
TONIGHT.
2) RAIN CHANCES RETURN FOR THURSDAY INTO THE WEEKEND. ISOLATED
STRONG TO SEVERE STORMS ARE POSSIBLE THURSDAY.
3) INCREASING CONFIDENCE IN THE DEVELOPMENT OF HOT AND HUMID
CONDITIONS NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
CROSSING SURFACE HIGH PRESSURE PROVIDES DRY AND QUIET WEATHER
THROUGH TONIGHT. LIGHT WIND AND RELATIVELY LOW HUMIDITY WILL
LEAD TO CONTINUED PLEASANT CONDITIONS UNDER A MOSTLY SUNNY SKY,
WITH TEMPERATURES JUST A FEW DEGREES BELOW CLIMATOLOGY. HIGH
CLOUDS BEGIN TO INCREASE TONIGHT ON WEST/SOUTHWEST FLOW ALOFT,
KEEPING LOW TEMPERATURES CLOSE TO NORMAL.
KEY MESSAGE 2...
A SHORTWAVE TROUGH SWINGS ACROSS THE GREAT LAKES ON THURSDAY AND
INTO THE NORTHEAST CONUS BY FRIDAY MORNING. ASSOCIATED SURFACE
LOW PRESSURE CROSSES SOUTHERN CANADA, PUSHING A SURFACE BOUNDARY
TOWARDS THE REGION BY THE END OF THE WEEK. THERE CONTINUE TO BE
SIGNS THAT THE BOUNDARY MAY STALL SOMEWHERE IN THE OHIO VALLEY
INTO THE WEEKEND, AS IT ALIGNS WITH QUASI-ZONAL MID-LEVEL FLOW.
THIS WILL KEEP PRECIPITATION CHANCES IN THE FORECAST EACH DAY
FROM THURSDAY THROUGH AT LEAST SATURDAY, WITH COVERAGE FAVORING
AREAS SOUTH OF PITTSBURGH FROM FRIDAY ON.
THE INITIAL PUSH OF SHOWERS AND STORMS THURSDAY AFTERNOON AND
EVENING WILL HAVE THE SUPPORT OF THE APPROACHING/CROSSING FRONT
AND TROUGH AXIS AND PERHAPS A PREFRONTAL SURFACE TROUGH. STORMS
SHOULD FIRE IN A FAVORABLE ENVIRONMENT, WITH HREF MEANS
SUGGESTING AROUND 1000 J/KG OF SURFACE-BASED CAPE AND 40-45
KNOTS OF 0-6KM SHEAR. SEVERE WEATHER SEEMS A POSSIBILITY, WITH
DAMAGING WIND GUSTS THE LIKELY MAIN THREAT.
GIVEN THE POSSIBILITY OF REPEATED ROUNDS OF SHOWERS AND
THUNDERSTORMS, RAINFALL TOTALS MAINLY FROM PITTSBURGH ON SOUTH
WILL NEED TO BE MONITORED INTO SATURDAY. STILL, PRECIPITABLE
WATER VALUES IN THIS REGION GENERALLY PEAK IN THE 85TH TO 90TH
PERCENTILE - NOT EXCESSIVE, BUT 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 3...
THE BOUNDARY MAY FINALLY LIFT BACK NORTH AS A WARM FRONT ON
SUNDAY. AFTER THIS, THERE IS BROAD ENSEMBLE AGREEMENT ON AN
IMPRESSIVE 500MB RIDGE BUILDING ACROSS THE LOWER MISSISSIPPI AND
OHIO RIVER VALLEYS, WHICH WOULD SPREAD TO ENCOMPASS OUR REGION
EARLY NEXT WEEK. THERE IS A HIGH PROBABILITY OF 500MB HEIGHTS
RISING ABOVE THE 500DM LEVEL BY TUESDAY NEXT WEEK. 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 /03Z WEDNESDAY THROUGH SUNDAY/
HIGH CONFIDENCE VFR WEATHER THROUGH THE TAF PERIOD. A MOSTLY
CLEAR SKY TONIGHT WILL BE FOLLOWED BY SCATTERED CUMULUS IN THE 4
TO 5 THOUSAND FOOT LAYER AFTER 15Z. THESE WOULD COLLAPSE WITH
SUNSET, AND BE FOLLOWED BY INCREASING HIGH CLOUDS AS SOUTHWEST
FLOW DEVELOPS ALOFT. SURFACE WIND WILL REMAIN LESS THAN 10 KNOTS
THROUGH THE PERIOD.
THE ONLY CAVEAT IS THE LOW PROBABILITY OF RIVER VALLEY FOG
BETWEEN 08Z-12Z, POTENTIALLY BECOMING DEEP ENOUGH TO IMPACTS
TERMINALS LIKE HLG/MGW/FKL DUE TO THE COMBINATION OF CLEAR SKY,
LIGHT WIND, AND COOL TEMPERATURES OVER WARMER RIVER WATER. THIS
SHOULD MAINLY MANIFEST AS STEAM FOG AND REMAIN AWAY FROM
TERMINALS, BUT A MODEST POTENTIAL FOR A FEW HOURS OF IMPACT
EXISTS.
OUTLOOK...
A MORE ACTIVE WEATHER PATTERN BEGINS THURSDAY AFTERNOON/EVENING
INTO THE WEEKEND AS MULTIPLE WAVES SUPPORT PERIODIC SHOWER AND
THUNDERSTORM CHANCES WITH VARYING DEGREES OF RESTRICTIONS (WHICH
WILL BE SOMEWHAT DEPENDENT ON COVERAGE OF DAYTIME RAIN).
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...CL
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