The National Weather Service has posted a *Winter Weather Advisory* for most of the area for tonight into tomorrow. All indications are that a slug of snowfall will impact the area from this evening into tomorrow morning. That being said, most guidance has converged on lower snow totals than were seen as being possible earlier in the week. Even so, the Euro model still indicates a shot at low-end warning criteria. In general, I think the NWS call for 1-3 inches of snow tonight is solid. I think it could push into the 2-4 inch range in spots that get better snowfall rates.
The second wave looks to miss the DC-Baltimore corridor to the south. However, it's not out of the range of possibilities for this to trend back north. This second part of the system would be from later on Thursday and into Friday.
TL;DR - A general 1-3 inches for much of the area tonight into tomorrow. Roads may be dangerous for travel. Some areas could see a bit higher. The second wave is still uncertain but for now, looks to miss.