561
FXUS61 KPBZ 080610
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
210 AM EDT SAT AUG 8 2026
WHAT HAS CHANGED
THE OVERALL FORECAST REMAINS LARGELY ON TRACK. THE MAIN CHANGE
WAS AN INCREASE FOR THE POTENTIAL FOR EXCESSIVE RAINFALL ON
MONDAY, WITH SEVERE CHANCES ALSO LIKELY TO PEAK ON THAT DAY.
KEY MESSAGES
1) A MORNING ROUND OF NUMEROUS TO WIDESPREAD SHOWERS AND STORMS
WILL PROVIDE MAINLY A CONTINUED HEAVY RAIN THREAT, WHILE A LATE
EVENING/OVERNIGHT ROUND WILL BE MORE SCATTERED BUT PRESENT A
SLIGHTLY HIGHER WIND GUST POTENTIAL.
2) AFTER A BREAK ON SUNDAY, DAILY SHOWER AND THUNDERSTORM
CHANCES RETURN MONDAY AND REMAIN IN THE FORECAST THROUGH AT
LEAST THURSDAY, WITH THE CONTINUED PRESENCE OF SEVERE AND
FLOODING THREATS.
DISCUSSION
KEY MESSAGE 1...
ALTHOUGH A RELATIVE LULL IN ACTIVITY IS IN PLACE AS OF THIS
WRITING, ADDITIONAL SHOWERS AND THUNDERSTORMS HAVE FORMED IN
OHIO, IN ADVANCE OF A SHORTWAVE IN THE GENERAL GREAT LAKES/NE
CONUS TROUGH. THIS ACTIVITY SHOULD SPREAD EASTWARD THROUGH THE
MORNING, IMPACTING THE UPPER OHIO VALLEY ESPECIALLY BETWEEN 07Z
AND 12Z.
SEVERE THREAT WITH THIS ACTIVITY SHOULD REMAIN QUITE LOW WITH
LITTLE LOW-LEVEL INSTABILITY IN PLACE. HOWEVER, THE COLUMN WILL
REMAIN FAVORABLE FOR EFFICIENT RAINFALL PRODUCTION AND HIGH
PRECIPITATION RATES. PRECIPITABLE WATER VALUES WILL REMAIN IN
THE 1.7 TO 1.8 INCH RANGE IN THE ONGOING SOUTHWEST FLOW. NEAR-
TERM MODEL SOUNDINGS SHOW WARM CLOUD DEPTHS OF 10K-12K FEET
ALONG WITH DECENT LOW-LEVEL SATURATION. ALTHOUGH INDIVIDUAL
CELLS WILL HAVE SOME MOTION, SOME TRAINING IS POSSIBLE AS MEAN
FLOW MAY ALIGN WITH A WSW-OREINTED LOW LEVEL JET, SUGGESTING
SOME TRAINING IS POSSIBLE. THE 00Z HREF SUGGESTS SOME 1-2" 6-HOUR
MAXIMUM RAINFALL TOTALS ARE POSSIBLE, WHICH COULD BE AN ISSUES
IF SUCH TOTALS HIT THE WRONG AREAS, SUCH AS THE LOCATIONS NEAR
AND EAST OF PITTSBURGH THAT RECEIVED HEAVIER RAIN ON FRIDAY, AND
THOSE AREAS WILL BE MONITORED CLOSELY. STILL, THE THREAT OF
FLOODING SHOULD REMAIN TOO ISOLATED AND FOR TOO SHORT A PERIOD
FOR THE ISSUANCE OF A WATCH.
MOST OF THIS ACTIVITY SHOULD DEPART AFTER 13Z OR SO WITH THE
INITIAL SHORTWAVE. AFTER A LULL, ANOTHER ROUND OF LIKELY MORE
SCATTERED SHOWERS AND STORMS IS EXPECTED DURING THE LATE
AFTERNOON THROUGH AROUND MIDNIGHT OR SO WITH ANOTHER SHORTWAVE
IN THE FLOW. WITH A DRIER OVERALL COLUMN BY THAT POINT AND
CORRESPONDINGLY MORE SUBDUED PWAT OF 1.2 TO 1.5 INCHES, THE
HEAVY RAIN THREAT SHOULD BE A LITTLE LOWER. NEVERTHELESS, THAT
DRIER AIR ALOFT WILL HELP TICK UP THE THREAT OF GUSTY TO
BORDERLINE SEVERE WINDS, AS 1500-2000 J/KG OF SURFACE-BASED
CAPE AND AROUND 1000 J/KG OF DOWNDRAFT CAPE APPEAR LIKELY AT
LEAST INTO THE EARLY TO MIDDLE EVENING HOURS.
KEY MESSAGE 2...
THE SECOND ROUND SHOULD END BY 06Z TONIGHT, AND THEN A NEEDED
BREAK STILL APPEARS LIKELY THROUGH SUNDAY AND SUNDAY NIGHT.
MODEL SOUNDINGS CONTINUE TO SUGGEST A DRIER COLUMN AND MID-LEVEL
CAPPING THAT WOULD PREVENT CONVECTIVE DEVELOPMENT. DEWPOINTS IN
THE MID AND UPPER 60S, AFTER TODAY'S READINGS IN THE 70S,
SHOULD LEND A LESS STICKY FEEL TO THE AIR.
THE OVERALL TROUGH REMAINS IN PLACE THROUGH MUCH OF NEXT WEEK.
DAILY SHOWERS AND THUNDERSTORM CHANCES REMAIN IN THE FORECAST
FOR MONDAY THROUGH AT LEAST THURSDAY, AS SEVERAL SHORTWAVE
RIPPLES CONTINUE TO RIDE THROUGH ON THE FLOW. HEAVY RAIN
POTENTIAL WILL NEED CONTINUED SCRUTINY, AS PRECIPITABLE WATER
VALUES REMAIN ABOVE-NORMAL IN A CLIMATOLOGIC SENSE. WPC WILL
LIKELY PLACE OUR REGION IN A SLIGHT (LEVEL 2 OF 4) RISK FOR
EXCESSIVE RAINFALL ON THAT DAY.
SEVERE WEATHER CHANCES SHOW AN UPTICK AS WELL, PARTICULARLY
EARLIER IN THE WEEK ACCORDING TO THE LONG-RANGE MACHINE-LEARNING
CONVECTIVE GUIDANCE. THIS MAKES SENSE, AS THIS PERIOD SHOWS THE
BEST JUXTAPOSITION OF INSTABILITY, MODERATE DEEP-LAYER SHEAR,
AND DECENT LOW-LEVEL FLOW. SOME UNCERTAINTY REMAINS AMONG THE
VARIOUS ENSEMBLE MEMBERS THAT WILL BE BETTER RESOLVED IN TIME.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AS ANOTHER SHORTWAVE BRINGS A RENEWED PUSH OF SUPPORT FOR LIFT,
CONVECTIVE COVERAGE IS FORECAST TO INCREASE FROM WEST TO EAST
OVERNIGHT AND THROUGH THE EARLY MORNING, WITH ACTIVITY ALREADY
NEAR ZZV. ALTHOUGH SOME WIND GUSTS OF 30 TO 40 MPH MAY BE
POSSIBLE, THE MAIN IMPACTS FROM THE STORMS WILL BE LIGHTNING
STRIKES AND PERIODS OF DOWNPOURS, WHICH COULD LEAD TO IFR/LIFR
VISIBILTIES FOR BRIEF PERIODS. HAVE USED 2-HOUR TEMPO GROUPS TO
ILLUSTRATE THE MOST-LIKELY PERIOD OF IMPACT. AWAY FROM STORMS,
IT APPEARS THAT VFR CONDITIONS WILL BE MOSTLY PREVALENT
INITIALLY (HREF SHOWS BEST FOG POTENTIAL ONLY NEAR DUJ), BEFORE
MVFR CEILINGS TAKE HOLD AROUND SUNRISE.
AFTER PRECIPITATION LARGELY DEPARTS BY 13Z OR SO, LINGERING
MVFR CEILINGS WILL SLOWLY LIFT AND ACHIEVE VFR BY MIDDAY/EARLY
AFTERNOON AS DAYTIME MIXING COMMENCES. SOUTHWEST WIND MAY GUST
TO BETWEEN 15 AND 20 KNOTS AS WELL. ANOTHER, MORE SCATTERED
ROUND OF CONVECTION APPEARS LIKELY TOWARDS THE END OF THE TAF
PERIOD, WHICH WILL BE HANDLED BY PROB30 GROUPS FOR NOW. ALTHOUGH
A DIRECT HIT AT ANY ONE AIRPORT WILL BE A LITTLE LESS LIKELY,
WIND GUSTS HAVE THE POTENTIAL TO BE STRONGER FOR THIS ROUND.
OUTLOOK...
SHORTWAVE RIDING SHOULD PROVIDE A NEEDED BREAK FROM CONVECTIVE
ACTIVITY ON SUNDAY. DAILY SHOWERS AND THUNDERSTORM CHANCES THEN
RETURN FOR MONDAY THROUGH WEDNESDAY, WITH RESTRICTIONS POSSIBLE.
PATCHY FOG AND STRATUS REMAINS POSSIBLE EACH MORNING WITH
STUBBORN LOW LEVEL MOISTURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...CL
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