A plume of moisture is on its way through the Tennessee Valley toward Southwest Virginia, where temperatures are cold and likely to support snow and sleet later this evening. A few bullet points for the evening:
* Winter weather advisories now cover Patrick, Floyd, Roanoke, Botetourt, and Rockbridge counties westward. Western Bedford and northern/western Franklin counties may see similar conditions to the winter weather advisories just west. I would not be surprised to see these advisories advance eastward and southeastward a bit later.
* We’ve batted around 1-4 inches for the last couple of days for likely accumulations, at least from Roanoke north and west. No reason to change that now. General rule on accumulations in Roanoke Valley and points north and west: Expect 2 inches, some will get a bit less, some a bit more. 4+ looks unlikely, unless there is some sort of heavy band that sets up over one area for a long time.
* Clouds today have held surface/low-level temperatures well below forecasts, with highs in mid 30s to near 40. In a marginally cold situation, this can make all the difference. More will likely fall as snow and sleet. There may now be little or no rain at all from Roanoke west and north.
* Area of precipitation looks solid and fairly intense. It is moving very fast though. May arrive in I-77 corridor by 9 p.m. and overspread region near midnight. You can follow it on Radar-Future Cast.
* Speed of system may mean most of the significant precipitation will be over near sunrise, no later than mid-morning. Melting will commence soon after it stops, with highs likely poking into the 40s most areas on Saturday. But Saturday morning is likely to be slippery in much of our region.