235
FXUS61 KRNK 212010
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
410 PM EDT TUE JUL 21 2026
WHAT HAS CHANGED
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR MOST OF THE AREA
EAST OF INTERSTATE 77. DAMAGING WINDS ARE THE MAIN THREAT, BUT
HAIL AND AN ISOLATED TORNADO OR TWO CANNOT BE RULED OUT.
A FLOOD WATCH IS ALSO IN EFFECT THROUGH TOMORROW FOR THE ENTIRE
AREA.
KEY MESSAGES
1) A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10 PM
TONIGHT, AND A FLOOD WATCH IN EFFECT FOR THE ENTIRE AREA THROUGH
TOMORROW FOR STRONG TO SEVERE SHOWERS AND THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1...A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH
10 PM TONIGHT, AND A FLOOD WATCH IN EFFECT FOR THE ENTIRE AREA
THROUGH TOMORROW FOR STRONG TO SEVERE SHOWERS AND THUNDERSTORMS.
THE LATEST SURFACE ANALYSIS SHOWS A WARM FRONT WELL NORTHEAST
OF THE AREA, WITH A COLD FRONT STRETCHING FROM THE EASTERN GREAT
LAKES TO IL AND WESTWARD. THIS WILL BE THE MAIN DRIVING FORCE
FOR SEVERE WEATHER LATER THIS EVENING. ALOFT, TROUGHING
ENCOMPASSES MUCH OF THE EASTERN STATES ALONG AND NORTH OF THE
MID ATLANTIC REGION.
THE FIRST WAVE OF POSITIVE VORTICITY ADVECTION WAS SHIFTING INTO
THE AREA AND HAD SPARKED A LINE OF STORMS MOVING THROUGH SE
WV AND INTO NORTHERN VA. THESE STORMS ARE MAINLY A FLOOD THREAT
IF THEY CONTINUE TO TRAIN. AS THEY SHIFT SOUTH AND INTERACT
WITH ADDITION INSTABILITY THIS AFTERNOON AND EVENING, EXPECT A
FEW STRONG TO SEVERE STORMS. ALONG THE COLD FRONT, MORE
WIDESPREAD CLUSTERS OF MULTICELLS PUSH SOUTH AFTER 4 TO 5 PM
AND TONIGHT. WET MICROBURSTS WILL BE THE MAIN CONCERN TODAY AND
TONIGHT, ALTHOUGH ALL CONVECTION MAY HAVE TORRENTIAL RAINFALL.
SHEAR BETWEEN 0-6 KM INCREASES TO 35 TO 45 KTS BY LATER THIS
AFTERNOON AND EVENING AS THE NOSE OF THE 300MB UPPER LEVEL JET
REACHES THE AREA, ALONG AND NORTH OF THE FRONT. ALSO CONCERNING
WILL BE THE INCREASING 0-1 KM SHEAR THAT MAY REACH 25 KTS, IN
THE VICINITY OF THE FRONT WHERE SURFACE WINDS MAY BACK. THIS
POINTS TOWARDS INCREASING LOW LEVEL ROTATION RESULTING IN A FEW
SUPERCELLS AND A SMALL TORNADO RISK.
THE COLD FRONT LOOKS TO SLOW DOWN AS IT CROSSES THE FORECAST
AREA FROM NORTH TO SOUTH, STALLING SOMEWHERE IN VA OR NORTHERN
NC OVERNIGHT. THUS THE HIGH THREAT FOR URBAN, SMALL STREAM, AND
FLASH FLOODING WILL CONTINUE OVERNIGHT INTO TOMORROW WITH
TRAINING CELLS ALONG THE BOUNDARY. CAMS ARE ALSO HINTING AT AN
MCV OR TWO IN THE AREA TOMORROW MORNING, WHICH WOULD SUPPORT
STRONGER AND HEAVIER STORMS. ADDITIONAL DEVELOPMENT IS EXPECTED
TOMORROW, WITH ADDITIONAL SHORT WAVE ENERGY AND FAVORABLE
KINEMATICS MOVING INTO THE MID ATLANTIC REGION. ALONG THE
FRONT, THE FLOODING THREAT WILL CONTINUE THROUGH INTO TOMORROW
NIGHT.
AS DRIER AIR BEGINS TO WORK IN FROM THE NORTH BY THURSDAY,
CHANCES FOR RAIN SINK SOUTH. AFTER A BRIEF BREAK, MORE CHANCES
FOR SHOWERS AND STORMS RETURN FRIDAY INTO THE WEEKEND, AS
ADDITIONAL MID LEVEL SHORT WAVES MOVE THROUGH. WITH THE NUMEROUS
CHANCES FOR RAIN AND CLOUD COVER IN THE FORECAST, TEMPERATURES
WILL BE IN THE 70S FOR THE ENTIRE AREA THURSDAY THROUGH
SATURDAY.
AVIATION /20Z TUESDAY THROUGH SUNDAY/
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...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR VAZ007-009>020-
022>024.
FLOOD WATCH FROM 10 PM EDT THIS EVENING THROUGH WEDNESDAY
EVENING FOR VAZ032>035-043>047-058-059.
NC...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NCZ001-002-018.
FLOOD WATCH FROM 10 PM EDT THIS EVENING THROUGH WEDNESDAY
EVENING FOR NCZ003>006-019-020.
WV...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR WVZ042>044-507-508.
DISCUSSION...AS/SH
AVIATION...SH
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