Rain showers now getting closer.  Check out live Doppler.  A cold front with showers stretching from the Great Lakes to the Gulf is heading our way.  The front will sweep across the D.C. area around noon.  Our hyperlocal microcast simulation shows some moderate showers late morning to noon 

and a simulation from SUNY Stony Brook shows a similar detailed picture. 

High confidence we will see rain tomorrow until mid-afternoon : >)  Then some chilly air comes back on gusty northwest winds for some cool mid-March weather into the weekend.