A front that separates humid air from much drier air is stalled over central Virginia and the Ohio Valley. This boundary will begin to slowly move northward over the course of the next 48 hours. High altitude winds from the southwest over the boundary will bring patchy clouds to the sky Sunday. As dew points creep back into the upper 60s, enough moisture may be present in the lower atmosphere such that daytime heating may spark a stray late afternoon/early evening thundershower, especially south and west of the city.
We are expected isolated to scattered thunderstorms on Monday and scattered to widespread thunderstorms on Tuesday as a very potent cold front approaches from the Great Lakes. This cold front will then pass off the East Coast and sag south into the Carolinas by Wednesday, resulting in cooler, drier and more comfortable conditions to finish out the workweek.