The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... South central Carroll County in north central Maryland... Northwestern Howard County in central Maryland... North central Montgomery County in central Maryland... Southeastern Frederick County in north central Maryland... * Until 230 PM EDT. * At 142 PM EDT, a severe thunderstorm was located over Green Valley, or near Damascus, moving east at 20 mph. HAZARD...60 mph wind gusts and half dollar 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... Damascus, Eldersburg, Mount Airy, Sykesville, Green Valley, Monrovia, Henryton, Winfield, Lisbon, Gaither, Watersville, Poplar Springs, Woodbine and Carrolltowne. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. By The National Weather Service