The National Weather Service has included Arlington County in a Flash Flood Watch. The watch is in effect until 6:00 p.m.
From NWS:
THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS EXPANDED
THE* FLASH FLOOD WATCH TO INCLUDE PORTIONS OF MARYLAND…THE
DISTRICT OF COLUMBIA AND VIRGINIA…INCLUDING THE FOLLOWING
AREAS…IN MARYLAND…ANNE ARUNDEL…CALVERT…CHARLES…
HARFORD…HOWARD…MONTGOMERY…PRINCE GEORGES AND SOUTHERN
BALTIMORE. THE DISTRICT OF COLUMBIA. IN VIRGINIA…
ARLINGTON/FALLS CHURCH/ALEXANDRIA…CULPEPER…FAIRFAX…
LOUDOUN…NORTHERN FAUQUIER…ORANGE…PRINCE
WILLIAM/MANASSAS/MANASSAS PARK…SOUTHERN FAUQUIER…
SPOTSYLVANIA AND STAFFORD.* UNTIL 6 PM EDT THIS EVENING
* SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PRODUCE MODERATE TO
HEAVY RAINFALL THROUGH THE REST OF THE AFTERNOON. ONE TO THREE
ADDITIONAL INCHES COULD CAUSE FLOODING OR FLASH FLOODING.PRECAUTIONARY/PREPAREDNESS ACTIONS…
A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.