The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... Northwestern Montgomery County in central Maryland... South central Frederick County in north central Maryland... Northeastern Loudoun County in northern Virginia... * Until 400 PM EDT. * At 314 PM EDT, a severe thunderstorm was located near Point Of Rocks, or near Poolesville, moving east at 25 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, Boyds, Clarksburg, Adamstown, Monrovia, Barnesville, Dickerson, Beallsville, Tuscarora, Lucketts and Park Mills. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building.