466
FXUS61 KPBZ 131055
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
655 AM EDT THU AUG 13 2026
WHAT HAS CHANGED
THE RISK FOR SEVERE THUNDERSTORMS AND FLOODING HAS DECREASED
SLIGHTLY FOR THE THURSDAY NIGHT INTO FRIDAY PERIOD. HOWEVER,
SOME UNCERTAINTY REMAINS, AND RISKS REMAIN NON-ZERO.
KEY MESSAGES
1) SCATTERED SHOWERS EXITING BY SUNRISE. UNCERTAINTY CONTINUES
REGARDING NEXT WAVE OF SHOWERS/STORMS THURSDAY NIGHT INTO
FRIDAY. CURRENT TRENDS KEEP THE HIGHER IMPACTS TO OUR SOUTH AND
WEST, BUT SEVERE WEATHER AND FLASH FLOOD IMPACTS HAVE A NON-ZERO
LEVEL OF THREAT.
3) ADDITIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE POSSIBLE
INTO EARLY NEXT WEEK, BUT BREAKS BETWEEN ACTIVITY ARE LIKELY
WHILE SEVERE AND FLOODING RISKS CURRENTLY APPEAR LIMITED.
DISCUSSION
KEY MESSAGE 1...
SCATTERED SHOWERS WILL CONTINUE TO SWING ACROSS THE REGION
THROUGH 09Z, MAINLY NORTH OF I-70, WITH NO SIGNIFICANT IMPACT.
PRECIPITATION POTENTIAL PAST SUNRISE AND INTO THIS EVENING WILL
BE LARGELY SQUASHED BY THE PRESENCE OF FLAT MID-LEVEL RIDGING
AND SURFACE HIGH PRESSURE OVER OUR REGION. THE NEXT SHORTWAVE
RIDING IN THE NORTHWEST FLOW OVER THE SOUTHEAST CONUS RIDGE WILL
ARRIVE TONIGHT, WITH ADDITIONAL DISTURBANCES THROUGH FRIDAY.
GIVEN THE SHORTWAVES RIDING OVER A LOW-LEVEL WARM ADVECTION
PATTERN WITH A NEARLY STATIONARY EFFECTIVE BOUNDARY TO OUR
SOUTHWEST, THERE ARE INDICATIONS THAT TRAINING THUNDERSTORMS
PRODUCING HEAVY RAIN AND FLASH FLOOD RISKS WILL ONCE AGAIN BE A
THREAT SOMEWHERE IN THE OHIO VALLEY.
RIGHT NOW, HI-RES ENSEMBLE GUIDANCE INDICATES THAT SUCH AN AXIS
IS MOST LIKELY TO SET UP TO THE SOUTHWEST OF OUR REGION.
THE 00Z HREF/REFS BOTH KEEP THE AXIS OF HIGHEST MAX POTENTIAL RAIN
TOTALS THROUGH 00Z SATURDAY BACK TOWARDS THE MIDDLE OHIO VALLEY
AND INTO HUNTINGTON WV. THAT SAID, THERE ARE STILL A COUPLE HI-
RES MODEL SCENARIOS (IN PARTICULAR THE NAM) THAT BRING HIGHER
RAIN TOTALS AS FAR NORTH AS THE MASON-DIXON LINE, WHICH COULD
THREATEN STILL- VULNERABLE AREAS IN EASTERN OHIO. WHILE THE
MOST-LIKELY SCENARIO APPEARS TO KEEP THE MAIN FLOODING THREAT
OUT OF OUR AREA, CONTINUED VIGILANCE IS MERITED GIVEN THE
RELATIVELY POOR MODEL PERFORMANCE WITH THUNDERSTORM COMPLEXES IN
THIS PATTERN. MESOSCALE DETAILS, MOST OF WHICH WILL BE
INFLUENCED BY FUTURE CONVECTIVE ACTIVITY, WILL PLAY A LARGE ROLE
IN HOW THINGS PLAY OUT, AND AS SUCH, OVERALL CONFIDENCE IN THE
OUTCOME IS RELATIVELY LOW.
KEY MESSAGE 2...
THE SYNOPTIC PATTERN WILL UNDERGO LITTLE CHANGE THROUGH THE
COMING DAYS. THE PREDOMINANT FLOW SETUP (RIDGE SOUTH TO
SOUTHWEST OF REGION AND ZONAL TO NORTHWEST FLOW OVERHEAD) STAYS
INTACT POTENTIALLY THROUGH MID TO LATE NEXT WEEK. PERIODIC
SHOWERS AND THUNDERSTORMS, GENERALLY SHORTER IN DURATION
COMPARED TO THIS PAST WEEK, REMAIN POSSIBLE IN SUCH FLOW WHILE
TEMPERATURE LARGELY STAYS NEAR SEASONAL AVERAGES. SATURDAY IS
THE MORE LIKELY DAY OF BREAK FROM ACTIVITY AS EASTERN CANADA
SURFACE HIGH PRESSURE MAY BUILD SOUTH, BUT EVEN THAT SCENARIO
COULD CHANGE AS MODELS ATTEMPT TO BETTER TIME SHORTWAVE
MOVEMENT/TIMING.
LONGER-RANGE MACHINE LEARNING GUIDANCE CONTINUES TO SUGGEST THAT
BOTH SEVERE AND FLASH FLOOD RISKS REMAIN MORE LIMITED OVER THE
COMING DAYS THAN THE PREVIOUS SEVERAL DAYS. STILL, IT REMAINS
PRUDENT TO FOLLOW THE LATEST FORECAST TRENDS, AS THERE ARE STILL
SCENARIOS THAT COULD BRING US HIGHER THREATS THAN CURRENTLY
INDICATED.
AVIATION /12Z THURSDAY THROUGH MONDAY/
IFR STRATUS ENVELOPING MOST LOCATIONS NORTH OF I-70 AND LIFR FOG
SOUTH WILL SLOWLY ERODE/LIFT THROUGH THE MORNING AS DIURNAL
HEATING COMMENCES. EXPECT MOST TERMINALS TO RETURN TO VFR
HEIGHTS WITH SCATTERED TO OCCASIONALLY BROKEN CU DECKS IN WHAT
IS OTHERWISE A RELATIVELY QUIET WEATHER DAY. THE LONE DISRUPTION
IS A LOW PROBABILITY SHOWER NEAR FKL/DUJ BETWEEN 21Z-01Z AS A
WEAK FRONTAL BOUNDARY DROPS SOUTH OUT OF THE UPSTATE NY REGION.
VFR WITH INCREASING CIRRUS FAVORED OVERNIGHT, WHICH SHOULD DELAY
AND LIMIT ANY POTENTIAL STRATUS/FOG COVERAGE. LATEST GUIDANCE
ALSO LEANS SLIGHTLY LATER WITH THE ARRIVAL OF
SHOWERS/THUNDERSTORMS WITH ANOTHER WAVE, FAVORING AFT 12Z
FRIDAY.
OUTLOOK...
WEAK SHORTWAVE MOVEMENT MAY YIELD SHOWERS AND LOWER PROBABILITY
THUNDERSTORMS AT SOME POINT FRIDAY, THOUGH VARIANCES REMAIN IN
TIMING AS WELL AS AREAL COVERAGE. IF THESE FORM, LOOK FOR MVFR
VSBY RESTRICTIONS AND POTENTIALLY IFR CIGS TO FORM WITHIN AND
SHORTLY AFTER OCCURRENCE.
OTHERWISE, DRIER WEATHER IS FAVORED UNTIL THE NEXT SYSTEM
CROSSES THE REGION SUNDAY WITH MORE SHOWERS AND THUNDERSTORMS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...FRAZIER
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