UPDATE (5:08am): Adam Caskey here with an update to the timeline (see small image). The newest information this morning points toward slightly warmer temperatures during the day and delays the bulk of the precipitation until the second half of the day for the metro area. It still looks like a glancing blow to the metro area with higher potential south of D.C.
D.C. hasn't seen more than 2 inches of snow in almost two years! Could this change tomorrow? It's looking likely a storm system will develop over the Southeast and will bring moisture to the D.C. metro area. A few RAIN showers for your morning commute, but changing over to snow around lunch time. Expect a slushy, wet snow for the evening rush. Here's a nice timeline Bob Ryan put together showing the timing and precipitation type.