Before there is a new round of cold air, there will be a mild spurt, with three days of highs in the 60s possible for Roanoke and points south and east. Thursday will likely be the warmest day, with highs likely reaching the 60s — and maybe some low 70s — over just about all of southern and western Virginia. If this is realized, Thursday will be the warmest day the Roanoke and New River valleys have had since the first week of November. Friday’s warmth will be truncated by increasing clouds and showers, possibly turning into outright general rain for a time on Friday night. A strong Arctic cold front is approaching from the west, and warm and moist flow shifting from the southeast to southwest will be bunched ahead of it. The front will be temporarily delayed in its movement Thursday night into Friday as a new wave of low pressure moves along it, enhancing our chance of rain. Behind the front, parts of the central U.S. as far south as Texas will be experiencing ice and snow as this low moves through.
Then comes Sunday’s mess. Cold high pressure extending from the Upper Midwest across the Great Lakes to the Northeast will press Arctic air down the eastern side of the Appalachians as moisture streams northeastward from the Gulf of Mexico. Models have bounced back and forth a bit with the strength and depth of that cold air, but just about every solution yields at least some period of wintry mix — leaning more toward the icy stuff rather than the white fluffy stuff — for late Saturday night into Sunday morning, at least. The low-pressure system is expected to track west of our region late Sunday into early Monday, a track that typically sweeps in milder air aloft that eventually erodes the cold air. Deeper cold air would lead to a longer period of snow and sleet to begin, possibly even enough to accumulate an inch or two, before changing to freezing rain and rain. If the cold air near the surface is held in stubbornly by high pressure to the north and warmer air moves in aloft, the threat would increase for a significant to major widespread ice storm. Right now, my best guess would be a brief period of snow transitioning to a freezing rain/sleet mix that lasts into Sunday afternoon, before becoming a cold rain/spotty freezing rain situation in which some spots in Southwest Virginia continue to collect substantial ice while others edge above the freezing mark.
Next week’s rebound from Arctic air looks to last only one day, Monday, with highs maybe edging into the 50s for some, before another Arctic cold front slams in by Tuesday. There could be some very cold mornings toward the middle to latter part of next week behind this front.