The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... Northeastern Washington County in north central Maryland... Northwestern Carroll County in north central Maryland... Northern Frederick County in north central Maryland... * Until 515 PM EDT. * At 425 PM EDT, severe thunderstorms were located along a line extending from near Wilson-Conococheague to Boonsboro, moving east at 35 mph. HAZARD...60 mph wind gusts. 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, Thurmont, Emmitsburg, Taneytown, Walkersville, Smithsburg, Braddock Heights, Mount Aetna, Mount Lena, Clover Hill, Discovery-Spring Garden, Wolfsville, Myersville, Cavetown, New Windsor, Woodsboro, Union Bridge, Libertytown, Sabillasville and Fort Ritchie. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. By The National Weather Service, Sterling, Va.