The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... Western Howard County in central Maryland... Central Montgomery County in central Maryland... Southern Frederick County in north central Maryland... * Until 1000 PM EDT. * At 922 PM EDT, a severe thunderstorm was located over Boyds, or near Germantown, moving east at 30 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... Germantown, Rockville, Gaithersburg, Olney, Damascus, Poolesville, Aspen Hill, Montgomery Village, North Potomac, Redland, Colesville, Boyds, Rossmoor, Wheaton-Glenmont, Cloverly, Clarksburg, Glenmont, Burtonsville, Darnestown and Derwood. 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.