Arlington County is among the areas under a Flash Flood Watch Thursday afternoon through early Friday morning.
Forecasters say slow-moving storms may develop and drop several inches of rain in a short period of time.
More from the National Weather Service:
…FLASH FLOOD WATCH REMAINS IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT… NUMEROUS SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING HEAVY RAINFALL ARE EXPECTED TO APPROACH THE REGION THIS AFTERNOON AND CONTINUE PAST MIDNIGHT. LOCALIZED RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE EXPECTED. * RAPID RISES OF CREEKS AND STREAMS WILL BE POSSIBLE DUE TO TORRENTIAL RAINFALL, POTENTIALLY SPILLING BEYOND THEIR BANKS. IN ADDITION, LOW POINTS ALONG ROADWAYS MAY BECOME IMPASSIBLE DUE TO ACCUMULATING RUNOFF. FLASH FLOODING MAY DEVELOP QUICKLY. 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 posted today for much of the region (dark green). Focus will be I-81 today & metro corridor tonight. Be prepared to seek higher ground should flooding develop. Don't drive through flooded roadways, as this is a leading cause of death due to floods. pic.twitter.com/96HY4JY7GC
— NWS DC/Baltimore (@NWS_BaltWash) May 31, 2018