The region is locked into a pattern of mist and rain that should linger through the night. The wedge of cool air is locked into the Piedmont and will linger for another day or so.
The end result is low clouds and mist. The normally warm air this time of year will ride over the cooler, more dense air and the combination of the warm and cool generate the mist and fog.
The wedge shows some signs of breaking up or eroding by late Wednesday so there may be some more sunshine Thursday. Current thinking is that there may be some sunshine on Wednesday, but the timing of the retreat of the cool air is difficult to nail down. Safe bet is to add some time to what you are thinking, so I am going with Thursday for the sunny day, but we may see some clearing tomorrow.
The other feature with the wedge is the cooler pattern. Highs are well below normal once again. In fact, yesterday was the coolest August 15th ever in Roanoke, topping out at 69°, 18° below normal and 1° below the record of 70° set in 1992. This is called the “Record Low High Temperature” but is really confusing. I just call it the coolest day.
This cool weather stays in place over the weekend with the sunshine of Thursday yielding to the clouds and rain of the weekend. Spotty showers are likely on Friday with more widespread rain on Saturday and Sunday.
Localized flooding is a concern by the weekend as there will be little evaporation of the water in the ground due to the lack of heat and sunlight so the ground stays wet. Quick run-off is likely.