218
FXUS61 KPBZ 060646
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
246 AM EDT MON JUL 6 2026
WHAT HAS CHANGED
THE COMBINATION OF SATURATED GROUNDS AND THREAT FOR HEAVY RAIN
FOR SLOW MOVING THUNDERSTORM LED TO THE ISSUANCE OF A FLOOD
WATCH FOR THIS AFTERNOON AND EVENING.
KEY MESSAGES
1) FLOOD WATCH IN EFFECT FROM 11AM TO 11PM EDT ACROSS A LARGE
PORTION OF THE REGION DUE TO RISK FOR FLASH FLOODING.
2) MORE LIMITED FLOOD RISKS REMAIN FOR CONVECTIVE ACTIVITY
TUESDAY.
3) NON-ZERO SEVERE AND FLOOD RISKS RETURN LATE IN THE WEEK.
DISCUSSION
KEY MESSAGE 1...
THE REGION WILL REMAIN JUST EAST OF A SAGGING UPPER TROUGH AXIS,
MAINTAINING THE RECENT WARM/HUMID ENVIRONMENT THAT WILL RESULT
IN GENERALLY DIURNALLY DRIVE THUNDERSTORM ACTIVITY. THE LACK OF
SIGNIFICANT ENVIRONMENTAL CHANGES ALSO MEANS THAT THE MODESTLY
UNSTABLE (~1500 J/KG SBCAPE), WEAK SHEAR (~15-20KTS), AND HIGH
PWATS (90-95TH PERCENTILE) WILL ALLOW SLOW-MOVING THUNDERSTORMS
TO PRODUCE 2-3"/HR RAINFALL RATES (WITH POTENTIAL FOR LOCALLY
HIGHER) THAT POSE A FLOOD RISK. A FLOOD WATCH FOR FLASH FLOODING
WAS ISSUED ACROSS A LARGE PORTION OF THE REGION WHILE TAKING
INTO ACCOUNT: 1) WHERE ENVIRONMENTAL CONDITIONS AND MID-LEVEL
JET SUPPORT BEST ALIGN FOR FLOODING POTENTIAL; 2) AREAS NEARING
GROUND SATURATION AND/OR LOCATIONS HAVING PREVIOUSLY SEEN
FLOODING IN THE PRIOR DAYS. THE RISK PERIOD, LIKE SUNDAY, IS
LIKELY TO PEAK BETWEEN 3PM-7PM, BUT THE WATCH WAS EXTENDED LATER
TO ACCOUNT FOR FLOODING IMPACTS TO LINGER LATER INTO THE NIGHT.
LOCATIONS OUTSIDE THE WATCH AREN'T IMMUNE FROM FLOODING RISKS
BUT ARE JUST CONSIDERED LOWER PROBABILITY TO EXPERIENCE THIS DUE
TO EITHER LOWER CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND/OR
POTENTIAL FOR MORE RESILIENCY TO HIGHER RATES. THESE COMMUNITIES
SHOULD REMAIN ALERT AS ALTERATIONS TO THUNDERSTORM
DEVELOPMENT/POSITIONING/DURATION DUE TO CONVECTIVE OUTFLOW
INTERACTIONS COULD QUICKLY HEIGHTEN THE LOCAL RISK LEVEL.
OF A LOWER BUT NOT INCONSEQUENTIAL NOTE IS THAT ISOLATED
INSTANCES OF DAMAGING WIND VIA PRECIPITATION LOADING WITH THESE
WATER-HEAVY STORMS CAN'T BE RULED OUT. MOST STORMS MAY ONLY
PRODUCE GUSTS UP TO 45 MPH (IF THAT), BUT CONDITIONS REMAIN
FAVORABLE ENOUGH TO BEAR MONITORING THIS THREAT.
KEY MESSAGE 2...
THE SAGGING TROUGH IS FAVORED TO BEGIN CROSSING THE REGION
THROUGH THE DAY TUESDAY AND EVENTUALLY ALLOW DRY AIR AND
SUBSIDENCE TO DEVELOP IN ITS WAKE HEADING INTO WEDNESDAY. BUT
BEFORE THAT OCCURS, THE AFTERNOON AND EVENING IS FAVORED AGAIN
TO EXPERIENCE THUNDERSTORM DEVELOPMENT THAT FAVORS LOCATIONS
SOUTHEAST OF PITTSBURGH. ENOUGH DELAY IN THE PREVAILING
ENVIRONMENT CHANGES MEANS STORMS IN THIS REGION COULD STILL POSE
A FLASH FLOOD RISK (AND A FAIRLY LIMITED DAMAGING WIND THREAT)
THAT COULD INCREASE PENDING HOW MUCH RAIN THE AREA SEES WITH
TODAY'S ACTIVITY.
KEY MESSAGE 3...
OUTSIDE OF TERRAIN INDUCED CONVECTION WEDNESDAY, THE UPPER OHIO
RIVER VALLEY IS FAVORED TO EXPERIENCE CALMER WEATHER CONDITIONS
BEFORE THE NEXT UPPER LEVEL PATTERN CROSSES.
THAT UPPER LEVEL TROUGH ARRIVES FROM THE WESTERN GREAT LAKES
SOMETIME THURSDAY INTO FRIDAY, WITH SOME VARIANCES AMONG GLOBAL
MODELS IN ITS DEPTH/TIMING AS WELL AS POTENTIAL FOR A SECONDARY
TROUGH TO LIFT NORTHWARD OUT OF THE TN RIVER VALLEY. FINER
DETAILS ARE TOO CLOUDY TO STATE MUCH BEYOND SUGGESTING MORE
THUNDERSTORM CHANCES WITH SEASONABLE TEMPERATURE; THAT SAID,
THERE ARE SIGNALS THAT, PENDING HOW THE PATTERN DEVELOPS, SEVERE
AND FLOODING RISKS COULD RETURN TO VARYING DEGREES. IT IS BEST
TO JUST BE AWARE OF THIS POTENTIAL AT THIS TIME AND MONITOR
FORECAST TRENDS AS THE WEEK PROGRESSES.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE STAGNANT, HUMID AIRMASS WITH VARYING CLOUD DECKS REMAINS
RIPE FOR IFR TO LIFR STRATUS/FOG DEVELOPMENT THROUGH 13Z. BUT
THE LACK OF CONSISTENT CLEARING PLUS TERRAIN INFLUENCES MEANS
CONDITIONS MAY NOT BE PERSISTENT THE ENTIRE TIME; EXPECT
POTENTIAL FOR LARGE FLUCTUATIONS IN RESTRICTION LEVELS AS
CEILINGS DEVELOP/SCATTER AND VISIBILITIES RISE/FALL.
OUTSIDE OF BRIEF MVFR WITH CU DEVELOPMENT, THE REGION IS LIKELY
TO BECOME VFR BY NOON TODAY AS IT REMAINS IN THE WARM SECTOR OF
THE BROAD UPPER LOW. THE EXCEPTION MAY BE FKL/DUJ THAT APPEARS
TO BE SITTING NEAR A STALLED BOUNDARY THAT MAY FOSTER MVFR CIGS
FOR LARGE PORTIONS OF THE DAY EVEN OUTSIDE OF CONVECTION (THOUGH
TIMING ON IMPROVEMENTS OR LEVEL CHANGES IS UNCERTAIN). THAT WARM
SECTOR AGAIN WILL RESULT IN SCATTERED TO NUMEROUS THUNDERSTORM
DEVELOPMENT FAVORING 19Z-00Z; EXPECT BRIEF BUT GUSTY WINDS WITH
HEAVY RAIN REDUCING VISIBILITIES TO 2 MILES OR LESS AND THE
POTENTIAL FOR PROLONGED PERIODS OF LIGHTNING.
LITTLE AIRMASS CHANGES MEANS IFR/LIFR FOG/STRATUS MAY AGAIN
DEVELOP AFTER 00Z TONIGHT, PENDING BREAKS IN MID/UPPER LEVEL
CLOUD COVER.
OUTLOOK...
MVFR/IFR CONDITIONS ARE LIKELY TO START TUESDAY THEN LIFT TO
VFR, THOUGH LATER IMPROVEMENTS ARE POSSIBLE, AS THUNDERSTORMS
DEVELOP AGAIN IN THE AFTERNOON/EVENING (FAVORING SOUTHEAST OF
KPIT).
DRY AND VFR DEVELOPS AT MOST TERMINALS BY WEDNESDAY AFTERNOON
AMID BRIEF SUBSIDENCE BEFORE THE NEXT UPPER TROUGH PROVIDES
WIDESPREAD SHOWER/THUNDERSTORM CHANCES LATE IN THE WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING
FOR PAZ007>009-013>016-020>022-029-073>078.
OH...FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING
FOR OHZ040-041-050.
WV...FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING
FOR WVZ001-002.
DISCUSSION...FRAZIER
AVIATION...FRAZIER
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