The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... Southeastern Washington County in north central Maryland... Southwestern Frederick County in north central Maryland... East central Jefferson County in the Panhandle of West Virginia... * Until 515 PM EDT. * At 422 PM EDT, a severe thunderstorm was located near Boonsboro, or near Shepherdstown, moving east at 10 mph. HAZARD...60 mph wind gusts and quarter size hail. SOURCE...Radar indicated. IMPACT...Damaging winds will cause some trees and large branches to fall. This could injure those outdoors, as well as damage homes and vehicles. Roadways may become blocked by downed trees. Localized power outages are possible. Unsecured light objects may become projectiles. * Locations impacted include... Frederick, Brunswick, Braddock Heights, Clover Hill, Jefferson, Myersville, Keedysville, Sharpsburg, Rosemont, Rohrersville, Burkittsville, Gapland, Brownsville, Antietam, Bloomfield, Clifton, Arnoldtown, Moler Crossroads, Petersville and Bolivar. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. By the National Weather Service