Quick weather update, in watching a few sites it looks like Saturday morning is very car-friendly! As of right now we are a "go", and I'll update this thread tomorrow. If you are planning on attending and I don't have your email just yet, please PM it along as I'll be sending details out there.
http://forecast.io/#/f/38.9972,-77.2884
http://www.weather.com/weather/tenday/l/USVA0324:1:US
http://forecast.io/#/f/38.9972,-77.2884
http://www.weather.com/weather/tenday/l/USVA0324:1:US