Arlington County is currently under a Flash Flood Watch.
Though the sun is out now, forecasters warn that slow-moving thunderstorms will develop later today and could dump heavy rain on Arlington and other parts of the region.
More from the National Weather Service:
…FLASH FLOOD WATCH IN EFFECT THROUGH MIDNIGHT EDT TONIGHT… THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A * FLASH FLOOD WATCH FOR THE DISTRICT OF COLUMBIA, AND PORTIONS OF CENTRAL MARYLAND AND NORTHERN VIRGINIA, INCLUDING THE FOLLOWING AREAS, IN MARYLAND, ANNE ARUNDEL, CARROLL, CENTRAL AND SOUTHEAST HOWARD, CENTRAL AND SOUTHEAST MONTGOMERY, FREDERICK MD, NORTHERN BALTIMORE, NORTHWEST HARFORD, NORTHWEST HOWARD, NORTHWEST MONTGOMERY, PRINCE GEORGES, SOUTHEAST HARFORD, AND SOUTHERN BALTIMORE. IN VIRGINIA, ARLINGTON/FALLS CHURCH/ALEXANDRIA AND FAIRFAX. * THROUGH MIDNIGHT TONIGHT. * SLOW MOVING THUNDERSTORMS CAPABLE OF PRODUCING VERY HEAVY RAIN ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING. * HIGH RAINFALL RATES MAY LEAD TO RAPID RISES OF WATER IN LOW- LYING AND POOR DRAINAGE AREAS AS WELL AS SOME SMALL STREAMS. 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. &&
A Flash Flood Watch has been issued for portions of the region until midnight tonight. This includes the Baltimore and Washington metropolitan areas. pic.twitter.com/xvRwqNUIua
— NWS DC/Baltimore (@NWS_BaltWash) August 31, 2018