UPDATE 8:30 AM: A few flurries are zipping by through the Arctic cold-reinforcing winds this morning, gusting over 40 mph at times in higher elevations. Some parts of Virginia north of I-64 got 1-4 inches overnight from the quick-moving Alberta clipper-type disturbance. We still look to be on track for a few hours of light-moderate snow on Friday. Will update on that this evening. END UPDATE
UPDATE 12 MIDNIGHT, 1/23: Most of the light snow has stayed north of I-64 through late Wednesday evening, but some bands are shifting southward in West Virginia, and may drift as far south as the Roanoke and New River valleys in the morning hours. Minor accumulations, if any, are expected. Forecast guidance from Wednesday night is split on whether Friday’ s storm system looks to be more moist than earlier projected, so I’ll hold with ideas below on snow accumulations awaiting more data. END UPDATE
We’ve been bantering quite a bit about the potential for snow on Friday … and there’s actually a system diving southeast tonight that might leave a coating of white on some parts of western and central Virginia. The best chances of light accumulation of snow overnight will generally be north of the U.S. 460 corridor (Bluefield-Blacksburg-Roanoke-Bedford-Lynchburg), but continued upslope snow showers (northwest winds blowing up and over the Appalachian slopes, creating lift that condenses moisture into clouds and snow) may continue some squalls into the morning even into more of Southwest Virginia to the south of U.S. 460. Don’t be surprised if you see some flakes or even a skiff of white, probably not more than an inch for anyone. Beware traveling in the morning in case there are patches of snow on roads, especially north and west of Roanoke. As cold as it’s been, almost everything will stick. The National Weather Service in Blacksburg is projecting a dusting to half an inch possible overnight and early Thursday along/west of the Blue Ridge and along-north of U.S. 460.
The potential for significant snow on Friday has continued to tick upward, as it appears, at least for now, there will be sufficient moisture to overcome extremely dry air to reach the surface for a period of time as a low-pressure system moves eastward toward our entrenched Arctic air. My best guess now: 2 inches for Roanoke, 3 inches for the Blacksburg-Christiansburg area, 1-2 inches east of the Blue Ridge and Roanoke Valley; 2-5 inches along the Blue Ridge south of Roanoke (think Floyd County to Galax and Fancy Gap), through the New River Valley and points west and southwest; and 1-3 inches north of the Roanoke and New River valleys to the I-64 corridor, and perhaps beyond. There may be a few locally heavier amounts, but Friday’s system is likely to provide a fairly even distribution of snowfall amounts, and not likely to produce small bands of much heavier snow, as some systems do. It will move through fairly quickly, moving into our region by mid to late Friday morning and out by mid-evening Friday, with continuing upslope snows behind it west of I-81/I-77 corridors into Saturday morning.
Many locations in our region will stay below freezing through Sunday and won’t see 40 til Monday, with a warmup next week reaching the 50s by midweek.