412
FXUS61 KRNK 171032
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
632 AM EDT MON AUG 17 2026
WHAT HAS CHANGED
FLOOD WATCH IS CONTINUED FOR PORTIONS OF SE WEST VIRGINIA AND
WEST CENTRAL VIRGINIA.
AVIATION FORECAST UPDATED.
KEY MESSAGES
1) FRONTAL BOUNDARY WILL BRING SHOWER AND THUNDERSTORM CHANCES
THAT MAY CAUSE STRONG TO SEVERE WINDS AND LOCALIZED FLASH
FLOODING TO THE AREA.
2) DRY WEATHER RETURNS TUESDAY, WITH THE NEXT RAIN CHANCES
FORECAST THURSDAY THROUGH SATURDAY.
DISCUSSION
KEY MESSAGE 1... FRONTAL BOUNDARY WILL BRING SHOWER AND THUNDERSTORM CHANCES
THAT MAY CAUSE STRONG TO SEVERE WINDS AND LOCALIZED FLASH
FLOODING TO THE AREA.
A COLD FRONT LOOKS TO PUSH THROUGH THE AREA LATE TONIGHT, WHICH
WILL LEAD TO SHOWERS AND THUNDERSTORMS FOR AREAS ALONG AND
SOUTH OF THE 460 CORRIDOR. THE ENVIRONMENT OUT AHEAD OF THESE
STORMS LOOKS FAVORABLE FOR STRONG TO SEVERE WINDS AS SBCAPE
VALUES LOOK TO INCREASE TO AROUND 2000-2500 J/KG, DCAPE VALUES
WILL INCREASE TO AROUND 700-900 J/KG, AND DEEP LAYER SHEAR IN
THE 0-6 KM LAYER LOOKS TO INCREASE ACROSS THE AREA TO AROUND
25-30 KNOTS. THIS DEEP LAYER SHEAR WILL BE ENOUGH TO HELP
DEVELOP MULTICELLULAR CLUSTERS AND AN ISOLATED SUPERCELL
THUNDERSTORM OR TWO THIS AFTERNOON ALONG THE FRONTAL BOUNDARY.
OVERALL, LOW LEVEL SHEAR LOOKS TO BE RATHER WEAK, WHICH WILL
KEEP THE THREAT FOR ANY TORNADOES TO A MINIMUM, WITH NO SPC
THREAT FORECAST. GIVEN THE PARAMETERS ABOVE, THE LARGEST THREAT
WILL BE SEVERE WINDS WITH THE STRONGER STORMS THAT DEVELOP.
ALONG WITH A SEVERE THREAT, PWATS IN THE 1.7-2.1 INCH RANGE WILL
CONTINUE TO LEAD TO A LOCALIZED FLASH FLOOD THREAT WHERE THE
HEAVIEST THUNDERSTORMS DEVELOP. TRAINING STORMS MAY BRING
REPEATED ROUNDS OF HEAVY RAINFALL, WHICH CAN QUICKLY FILL LOCAL
STREAMS LEADING TO FLOODING OF ROADWAYS AND URBAN AREAS.
RAINFALL RATES IN THE 3-6 INCH PER HOUR RANGE MAY ALSO QUICKLY
AID IN FLASH FLOODING OCCURRING TODAY WITH THESE THUNDERSTORMS.
KEY MESSAGE 2... DRY WEATHER RETURNS TUESDAY, WITH THE NEXT RAIN CHANCES
FORECAST THURSDAY THROUGH SATURDAY.
BEHIND THE PASSAGE OF A COLD FRONT ON MONDAY, DRIER AIR IS
EXPECTED TO ADVECT INTO THE REGION. THIS WILL LEAD TO
SIGNIFICANTLY REDUCED SHOWER AND THUNDERSTORM CHANCES, WITH
NEAR ZERO CHANCES FORECAST TUESDAY AND WEDNESDAY FOR THE AREA.
AN UPPER LEVEL TROUGH AND ADDITIONAL COLD FRONT PUSHES INTO THE
AREA LATE THURSDAY, WHICH LOOKS TO BRING SHOWER AND THUNDERSTORM
CHANCES BACK INTO THE REGION. TEMPERATURES ALSO LOOK TO RETURN
TO SEASONAL VALUES AS THIS UPPER LEVEL TROUGH EFFECTIVELY
RETURNS THE UPPER LEVEL RIDGE BACK WEST INTO THE WESTERN CONUS
BY THE END OF NEXT WEEK. THE AFOREMENTIONED FRONTAL BOUNDARY
DOES LOOK TO GET HUNG UP ACROSS THE REGION THROUGH SATURDAY,
LEADING TO SCATTERED RAIN AND THUNDERSTORM CHANCES DAILY
STARTING THURSDAY ONCE AGAIN.
AVIATION /12Z MONDAY THROUGH FRIDAY/
WITH THE LATE NIGHT RAINFALL FOR MUCH OF THE AREA, THE REGION
HAS SO FAR REMAINED FOG AND LOW CIG FREE THIS MORNING, WITH ONLY
SOME MVFR CIGS AND VSBYS DEVELOPING AT LWB AND LYH. THESE
RESTRICTIONS SHOULD LIFT QUITE QUICKLY AFTER 12 UTC THIS MORNING.
CHANCES FOR SHRA/TSRA WILL RETURN TODAY FOR MOST TERMINALS
ALONG AND SOUTH OF 460, WITH ROA AND LYH POSSIBLY NOT SEEING
HIGH ENOUGH CHANCES TO INCLUDE IN A TAF LINE AT THIS TIME. THESE
SHOWERS AND THUNDERSTORMS MAY LEAD TO BRIEF PERIODS OF
RESTRICTIONS PLUS ERRATIC WINDS IF THEY MOVE OVER OR WITHIN THE
VICINITY OF A TERMINAL.
WINDS TODAY WILL PREDOMINANTLY REMAIN OUT OF THE WEST/NORTHWEST
AT AROUND 5-10 KNOTS WITH GUSTS UP TO 15-20 KNOTS AT TIMES.
OVERNIGHT FOG AND STRATUS LOOKS TO RETURN AGAIN MONDAY NIGHT
INTO TUESDAY MORNING.
OUTLOOK MONDAY NIGHT THROUGH THURSDAY NIGHT...
RAIN AND THUNDERSTORM CHANCES END FOR TUESDAY/WEDNESDAY, WITH
LIKELY OVERNIGHT FOG AND LOW STRATUS CONTINUING TO BE AN ISSUE.
CHANCES OF SHRA/TSRA RETURN THURSDAY AND FRIDAY WITH ANOTHER
COLD FRONTAL PASSAGE. MAINLY VFR OUTSIDE OF ANY STORMS AND LATE
NIGHT BR/STRATUS.
HYDROLOGY
FLOOD WATCH IN EFFECT THROUGH LATE MONDAY NIGHT FOR PARTS OF WV
AND VA......
AN ACTIVE UPPER LEVEL PATTERN WILL COMBINE WITH SURFACE
BOUNDARIES AND ADEQUATE INSTABILITY TO PRODUCE SEVERAL ROUNDS
OF SHOWERS AND STORMS THROUGH MONDAY NIGHT. A FLOOD WATCH HAS
BEEN ISSUED FOR PARTS OF SE WV AND ALONG THE WV/VA BORDER WHERE
FFG VALUES ARE LESS THAN 1.50 INCHES FOR 1 HOUR.
RNK WATCHES/WARNINGS/ADVISORIES
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ019-020.
NC...NONE.
WV...FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ042>044-507-508.
DISCUSSION...EB
AVIATION...EB
HYDROLOGY...SH
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