Arlington County and much of the D.C. region is under Flash Flood Watch from Friday afternoon to Saturday afternoon.
Forecasters say a slow-moving storm system is threatening to dump three inches or more of rain, starting Friday. Residents are being urged to take precautions near streams and creeks, in low-lying areas, and on the roads,
More from the National Weather Service:
… FLASH FLOOD WATCH IN EFFECT FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON… THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A * FLASH FLOOD WATCH FOR PORTIONS OF MARYLAND, THE DISTRICT OF COLUMBIA, VIRGINIA, AND WEST VIRGINIA… * FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON * LOW PRESSURE IS GOING TO DEVELOP OVER THE MID ATLANTIC FRIDAY AND REMAIN NEARLY STATIONARY THIS WEEKEND. THIS WILL HAVE THE POTENTIAL TO BRING 3 INCHES OR MORE OF RAIN TO THE REGION THROUGH SATURDAY AFTERNOON. THUNDERSTORMS COULD CAUSE LOCALLY HIGHER RAINFALL AMOUNTS. * HEAVY RAINFALL MAY RESULT IN RAPID RISES IN STREAMS AND CREEKS. THIS COULD QUICKLY RESULT IN FLOODING… ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREAS. PRECAUTIONARY/PREPAREDNESS ACTIONS… A FLASH FLOOD WATCH MEANS THAT CONDITIONS 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. 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 is in effect for a portion of the NWS Sterling forecast area Fri afternoon-Sat afternoon pic.twitter.com/M0VADUdQfU
— NWS DC/Baltimore (@NWS_BaltWash) July 27, 2017
Ready for the rain? Here's how much models are forecasting. More details: https://t.co/9GjbRvhzqH pic.twitter.com/LUxExl4P2b
— Capital Weather Gang (@capitalweather) July 27, 2017