The National Weather Service has confirmed that tornadoes touched down in Maryland and Virginia during Wednesday's storms that knocked out power to more than half a million customers in the region.
About 40,000 customers in the Washington region remained without power Friday.
By Thursday evening, the National Weather Service had determined that a tornado occurred in Maryland's Calvert County, near Chesapeake Beach, and in Virginia's Clarke County, near Millwood. Preliminary damage assessments also indicated that tornadoes likely touched down in Culpeper and Stafford counties.
The Maryland tornado was rated as a Category EF-O tornado, the weakest classification on the scale. It ran on a 1 1/2-mile path, knocking down trees and tearing roofs off several homes and a restaurant.
The Clarke County tornado was rated as a small EF-1 tornado, the next highest classification, with a path about a half-mile in length. It damaged a stand of trees.
The weather service said its survey teams are continuing to assess damage in the region.