Tonight
The latest 3-hour pressure falls indicate, as expected, a new low pressure area trying to develop near the South Carolina coast. The developing coastal storm will start to take over later this evening and overnight and strengthen rapidly as it moves up the coast. This will bring heavy precipitation to the region late this evening and continuing overnight.
Temperatures in the District and south and east are likely to rise to or above freezing for several hours during the overnight period before falling back down as the storm heads to our northeast.
Some areas inside the beltway, north and west of town, may remain below freezing for a longer period or for the entire storm.
Outside the beltway, locations such as Reston and Gaithersburg to our north and west may also see a period overnight where temps rise to near or slightly above freezing, but many areas are likely to remain below freezing for the entire event.
Bottom Line
Light to moderate ice accumulations are likely inside the Beltway, and major ice accumulation is likely to the north and west of DC outside the Beltway. Any ice accretion on power lines and trees will be exacerbated by very windy conditions overnight. The precipitation will likely end as a period of all snow Wednesday morning before it shuts off.
) so far today telling me how warm and sunny it was... oh yeah... he saw orange trees and got an autograph from some racecar pit crew turned sports announcer dude... 
