Nation’s Capital as seen from Arlington Virginia (image courtesy National Park Service)
Dew points are currently running in the lower teens across much of the Washington DC Metropolitan Area. Roadway temperatures are well below freezing and the frozen ground underneath the pavement is not going to be very helpful when rain begins to fall across the Washington Area between 11pm and 1am.
The image below (courtesy Tropical Tidbits) shows the latest future-cast radar from the High-Resolution-Rapid-Refresh (HRRR) model. A warm front will slide through the area inducing a period of light freezing rain. For those of you with travel plans, it would be a good idea to stay off the roadways late this evening.
The cold, dry wedge of air at the surface will initially evaporate some of the precipitation which will prevent temperatures from rising as fast as some of the models indicate. It is possible that freezing rain advisories may need to be extended further east to include the entire Metropolitan Area this evening.
Tonights forecast is difficult because some locations may in fact sit just above freezing during the pre-dawn hours and with a frozen ground acting to cool the lower 50 to 100 feet of the atmosphere we may have widespread slick roadways for the first half of the early morning rush hour.