203
FXUS61 KRNK 211025
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
625 AM EDT TUE JUL 21 2026
WHAT HAS CHANGED
ADJUSTED TEMPS DOWN SLIGHTLY DUE TO CLOUD COVER EXPECTED ACROSS
THE REGION THROUGH MOST OF THE DAY TODAY.
AVIATION UPDATE BELOW.
KEY MESSAGES
1) STRONG STORMS EXPECTED TODAY AND WEDNESDAY.
2) TEMPERATURES SHOULD TURN MORE SEASONABLE BY THE MIDDLE OF THE
WEEK AFTER A FRONTAL PASSAGE.
DISCUSSION
KEY MESSAGE 1...STRONG STORMS EXPECTED TODAY AND WEDNESDAY.
AN UPPER LEVEL SHORTWAVE TROUGH LOOKS TO PUSH THROUGH THE GREAT
LAKES REGION, AND AN ASSOCIATED COLD FRONT WILL PUSH INTO THE
OHIO VALLEY AND MID-ATLANTIC STATES THIS AFTERNOON AND EVENING.
BOTH OF THESE MECHANISMS WILL PROVIDE AMPLE FORCING FOR ASCENT
ACROSS THE REGION FOR WIDESPREAD SHOWER AND THUNDERSTORM
DEVELOPMENT.
WITH THE NOSE OF A STRONG 250MB JET STREAK PUSHING INTO THE
REGION FROM THE NORTHWEST TODAY, DEEP LAYER SHEAR LOOKS TO BE IN
THE 40-60 KNOT RANGE THROUGH THE AFTERNOON AND EVENING AREAS,
ESPECIALLY FOR AREAS ALONG AND NORTH OF I-64 WHERE BETTER SHEAR
WILL BE PRESENT. FORECAST CAM SOUNDINGS INDICATE THAT SOME LOW
LEVEL CLOCKWISE TURNING HODOGRAPHS LOOK DEVELOP; HOWEVER, WITH
SOUTHWESTERLY FLOW AT THE SURFACE TODAY, THE AMOUNT OF CLOCKWISE
TURNING LOOKS TO REMAIN MODEST AT BEST. THE BEST SHEAR AND
HODOGRAPH PROFILES LOOK TO ARRIVE WITH THE ACTUAL COLD FRONT
THAT MAY NOT ARRIVE INTO THE FORECAST AREA UNTIL AFTER 00 UTC.
AS THE COLD FRONT ARRIVES, WINDS LOOK TO BACK OUT OF THE
SOUTHEAST, WHICH PROVIDES A MUCH MORE IMPRESSIVE CLOCKWISE
TURNING HODOGRAPH. THE LARGEST TORNADO THREAT WILL LIKELY BE
ACCOMPANIED BY THE APPROACH AND PASSAGE OF THE FRONT; HOWEVER,
WITH TIMING UNCERTAINTY, AND POSSIBLE LACK OF DAYTIME HEATING,
THE THREAT FOR ANY TORNADO WILL BE DEPENDENT ON ALL OF THESE
INGREDIENTS COMING TOGETHER AT ONCE. CAM GUIDANCE DOES HAVE A
MESSY CONVECTIVE EVOLUTION THIS AFTERNOON AND EVENING; HOWEVER,
MULTICELLULAR CLUSTERS, WITH A SUPERCELL OR TWO CAN'T BE RULED
OUT. SOME MULTICELLULAR CLUSTERS MAY HAVE BOWING LINE SEGMENTS
ASSOCIATED WITH THEM GIVEN THE AMOUNT OF DEEP LAYER SHEAR
PRESENT TODAY.
OVERALL THE CONFIDENCE IN TORNADOES AND HAIL ARE LOW GIVEN THE
UNCERTAINTIES MENTIONED ABOVE. THE MOST IMPACTFUL THREAT
EXPECTED FOR TODAY IS DAMAGING WIND GUSTS, WHICH WILL LEAD TO
THE POTENTIAL FOR NUMEROUS DOWNED TREES AND POWER POLES ACROSS
THE AREA. THIS WILL LIKELY INADVERTENTLY LEAD TO THE POSSIBILITY
FOR MORE WIDESPREAD POWER OUTAGES ACROSS THE AREA GIVEN THE MORE
WIDESPREAD NATURE OF STORMS EXPECTED TODAY.
IN TERMS OF EVOLUTION, IT LOOKS LIKE THERE COULD BE TWO ROUNDS
OF STORMS TODAY, WITH EARLY AFTERNOON CONVECTION DEVELOPING
ACROSS THE MOUNTAINS AND PUSHING EAST, AND THEN AN ADDITIONAL
ROUND IN THE LATE EVENING AS THE COLD FRONT PUSHES INTO THE
REGION. THIS SECOND ROUND LOOKS TO ARRIVE AT SUNSET OR LATER FOR
MOUNTAIN LOCATIONS.
ON WEDNESDAY, THE AFOREMENTIONED FRONT LOOKS TO GET HUNG UP IN A
EAST/WEST ORIENTATION ALONG THE VA/NC BORDER PROVIDING A FOCAL
POINT FOR SHOWER/THUNDERSTORM ACTIVITY PRIMARILY SOUTH OF 460.
SO FAR IT APPEARS THAT DAMAGING WINDS AND A TORNADO OR TWO CAN'T
BE RULED OUT ON THE EASTERN SIDE OF THIS FRONTAL BOUNDARY IN THE
PIEDMONTS OF VA/NC ON WEDNESDAY AFTERNOON. EVENTUALLY, THIS
FRONT LOOKS TO PUSH SOUTH LATE WEDNESDAY NIGHT, AND BY THURSDAY,
ENOUGH DRY AIR ADVECTING INTO THE AREA LOOKS TO END ANY RAIN
CHANCES FOR AT LEAST ONE DAY.
KEY MESSAGE 2...TEMPERATURES SHOULD TURN MORE SEASONABLE BY THE
MIDDLE OF THE WEEK AFTER A FRONTAL PASSAGE.
STRONG SUMMERTIME FRONT PASSING THROUGH THE REGION TONIGHT WILL
BRING A LARGE PATTERN CHANGE TO THE AREA STARTING LATE WEDNESDAY
INTO THURSDAY. BEHIND THE PASSAGE OF THE FRONT, UPPER LEVEL
TROUGHING LOOKS TO SETTLE ACROSS THE EASTERN CONUS THROUGH MUCH
OF THE WORK WEEK. THIS WILL KEEP 500MB HEIGHTS MUCH LOWER ACROSS
THE REGION LEADING TO OVERALL COOLER TEMPERATURES. SURFACE HIGH
PRESSURE COMING OUT OF CANADA WILL ALSO LOWER DEWPOINTS INTO
THE 50S AND 60S WHICH WILL MAKE IT FEEL MUCH MORE COMFORTABLE
OUTSIDE DURING THE PEAK HEAT OF THE DAY. HIGHS LOOK TO ONLY
CLIMB INTO THE UPPER 70S TO LOW 80S ACROSS THE MOUNTAINS, AND
MID TO UPPER 80S ACROSS THE PIEDMONT STARTING WEDNESDAY, AND
CONTINUING THROUGH SATURDAY BEFORE TEMPERATURES LOOK TO INCREASE
AGAIN ON SUNDAY OF NEXT WEEK. SHOWER AND THUNDERSTORM CHANCES
BEYOND THE FRONTAL PASSAGE TUESDAY NIGHT WILL PRIMARILY BE
RELEGATED TO MOUNTAIN LOCATIONS, AND LOOK TO REMAIN ISOLATED,
WHERE OROGRAPHICAL LIFT CAN ENHANCE DEVELOPMENT DURING PEAK
HEATING. WHILE CHANCES LOOK TO BE MINIMAL ON THURSDAY, THEY
SLOWLY START TO INCREASE ON FRIDAY AND INTO THE WEEKEND.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
SOME MVFR TO LIFR CIGS AND VSBYS ARE BEING OBSERVED ACROSS THE
REGION THIS MORNING AT SEVERAL TERMINALS. THESE RESTRICTIONS
LOOK TO LINGER FOR THE NEXT COUPLE OF HOURS THIS MORNING BEFORE
LIFTING TO VFR LEVELS. THERE ARE ALSO SOME LINGERING SHOWERS
THAT HAVE BEEN PUSHING THROUGH THE VICINITY OF BLF THIS MORNING.
WITH A FRONTAL BOUNDARY PUSHING TOWARDS THE AREA TODAY,
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE
REGION, WHICH WILL LEAD TO BRIEF PERIODS OF MVFR TO IFR
RESTRICTIONS IF THEY MOVE IN THE VICINITY OF ANY TERMINALS.
THESE THUNDERSTORMS LOOK TO CONTINUE THROUGH THE END OF THE TAF
PERIOD AS THE FRONTAL BOUNDARY ARRIVES LATER IN THE EVENING
BETWEEN 00-06 UTC. THIS WILL PROVIDE RAIN SHOWERS AND
THUNDERSTORMS DURING THIS PERIOD FOR MOST TERMINALS. THESE
SHOWERS AND THUNDERSTORMS WILL HAVE THE POTENTIAL FOR PRODUCING
STRONG AND ERRATIC WINDS, AS WELL AS SOME HAIL AND AN ISOLATED
TORNADO CAN'T BE RULED OUT.
WINDS THROUGHOUT TODAY LOOK TO REMAIN OUT OF THE SOUTHWEST AT
AROUND 10-15 KNOTS, WITH GUSTS UP TO 20-25 KNOTS THROUGH THE
AFTERNOON AND EVENING TIMEFRAME.
MVFR TO IFR CIGS AND VSBYS LOOK TO RETURN AFTER 03 UTC WEDNESDAY
TO ALL TERMINALS.
CONFIDENCE IN THE ABOVE FORECAST IS MODERATE.
EXTENDED AVIATION OUTLOOK...
SHOWER AND STORM CHANCES PERSIST ON WEDNESDAY, KEEPING LIKELY
SUB-VFR CONDITIONS IN PLACE AREA- WIDE WHEN IMPACTING A
TERMINAL. LWB MAY BE JUST FAR ENOUGH NORTH TO AVOID RAIN, BUT
EVEN SO, WOULD LIKELY FOG IN TUESDAY NIGHT. DRIER CONDITIONS
MOVE IN FOR THURSDAY AND FRIDAY, WITH NO RAIN CHANCES OUTSIDE OF
DAN, THOUGH ONLY ISOLATED IN COVERAGE. BETTER RAIN CHANCES
RETURN FOR SATURDAY. OVERNIGHT FOG WILL REMAIN POSSIBLE EACH
NIGHT, PARTICULARLY AT LWB.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...NONE.
WV...NONE.
DISCUSSION...EB
AVIATION...EB/JCB
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page