Total snowfall accumulations are likely to be 5-10 inches in the immediate metro region, with up to 8-14 inches in the colder suburbs west of DC (western Fairfax County).
http://www.washingtonpost.com/blogs/capital-weather-gang-live/liveblog/heavy-snow-tonight-then-mixed-precipitation-thursday-live-forecast-updates/
http://www.washingtonpost.com/blogs/capital-weather-gang-live/liveblog/heavy-snow-tonight-then-mixed-precipitation-thursday-live-forecast-updates/