Flash flood warnings were issued as strong storms moved through northern Virginia, Maryland, and Washington DC on Friday morning, August 9,Footage posted at 8:40 am by Tony Castrilli, the Director of Public Affairs for Fairfax County, Virginia, shows rain falling in his yard in Mount Vernon, about 13 miles south of Washington after a rare tornado warning was issued for the wider area.Though the tornado warning had passed, Castrilli urged residents to “stay alert” as a flash flood warning remained in effect until 11 am local time. Credit: Tony Castrilli via Storyful