Everybody run out and buy up as much bread, milk, and toilet paper as you can for this one. It is actually going to be a blizzard. 6 to 12 inches is the current most likely but as DC area storms usually are it could go either way, such as up to 2 FEET.
http://blog.washingtonpost.com/capitalweathergang/
Remember that you don't know how to drive in the snow so please don't.