The image above shows our next two waves of rainfall moving through the Washington Area. The image is courtesy TropicalTidbits and the forecast model is the NAM, or North American Model (a short-range model).
The time-lapse loop (future-cast image above) begins at 01z (Zulu, or 8PM this evening) and runs through 00z Wednesday (7pm Tuesday EST).
Bottom Line Up Front (BLUF):
- Heaviest rain should remain south and east of D.C. on Monday with a lull in activity on Monday evening across our area.
- A wave of moderate to potentially heavy rainfall is likely across the immediate Washington Area during the day on Tuesday.
How much rainfall could fall across the Mid-Atlantic?
Most locations should pick up around a half-inch of rain with some locations across southern Maryland picking upwards of 1 to possibly 2″ of rain.
DC Storms 
It still looks like some snow potential (probably light) around Thursday night and again late in the weekend and following week. It is a very complex situation with several systems possibly coming into play.
One thing appears certain. It is going to be very cold from late this week into the following week. If you want to hope for snow, it is great to have a lot of cold air around!