A Flash Flood Watch is in effect until 8 p.m. in Reston and surrounding areas.

The National Weather Service expects showers and thunderstorms to produce areas of localized flooding.

Here’s more from the alert:

* SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING VERY HEAVY RAINFALL ARE EXPECTED ACROSS THE AREA THIS AFTERNOON AND INTO THE EVENING. THIS HEAVY RAIN MAY LEAD TO LOCALIZED TOTAL 

RAINFALL AMOUNTS OF UP TO 3 INCHES. MUCH OF THIS RAIN MAY FALL  IN SHORT PERIODS OF TIME IN ANY GIVEN LOCATION, RESULTING IN THE

RISK FOR 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.

Severe thunderstorms are possible this afternoon into early evening, with damaging winds being the primary threat. Heavy rainfall will also be possible, potentially leading to isolated instances of flash flooding. pic.twitter.com/U7FdAoJ0iX

— NWS DC/Baltimore (@NWS_BaltWash) July 31, 2019