There has been some mention on here for a nearly a week about a potential weekend storm system that could bring snow to Southwest Virginia. It appears likely that storm system will develop, and it may bring some snow, but it probably comes together just a little too late for widespread accumulating snowfall in our region. The Hydrometorological Prediction Center shows a surface low-pressure system likely to develop about Danville or so, with computer model projections (the little orange squares) starting it in various locations across Virginia and a few in North Carolina. This will develop as upper-level energy rounds a trough — or southerly dip in the jet stream — that will re-introduce Arctic air late Friday into the weekend . The arrival of the front, the disturbance and the surface low formation may result in a period of showers or snow showers Friday afternoon into Saturday morning in our general region. Obstacles to significant snowfall for the Roanoke and New River valleys, and most of our region east of Interstate 77 and south of Interstate 64, include: (1) limited moisture with no direct Gulf of Mexico connection, (2) surface temperatures likely starting well above freezing, in the 40s and 50s, so early precipitation may reach the ground as rain, (3) northwesterly winds behind the front quickly drying out the moisture with downslope flow in much of our region; (4) the lateness of the developing surface low, which is more favorable for precipitation to our north and east. The HPC has re-introduced a solid-white dry slot in its 1-inch snow probability map from about Roanoke southward, and thin 5-30 percent chances for most surrounding areas. Snowfall chances pick up to the west of Interstate 77, largely because of a prolonged upslope snow period with northwesterly winds behind the storm, and to the northeast in central and northern Virginia, where the developing surface low may have more impact and draw in some Atlantic moisture as it moves northeast. Upslope snow squalls will continue in West Virginia, high ridges near the Virginia-West Virginia border, and locations west of Interstate 77 through Saturday night and into Sunday, with some of the typical upslope snow belts getting several inches. A few of these snow squalls may squirt eastward into the New River Valley with some whiteness coating the ground in spots on Saturday evening, and a few snow showers and flurries may fly in cold northwest winds even into the Roanoke Valley. High temperatures likely don’t get above 40 in Roanoke and struggle to make freezing in the New River Valley and points west this weekend, with lows dipping into the teens to lower 20s many spots by Sunday and Monday mornings.
As has been commonly the case this winter, the Arctic air will not stick around, but swing eastward quickly, and we’ll warm back up into the 50s next week. More than anything, next week looks to be a wet one for Southwest Virginia and much of the East, with storm systems Tuesday and then again about 3 days later. The second one in particular may be very strong, with widespread weather mayhem of many types in the central and eastern U.S. There is some chance its moisture will catch wedged-in cold air for some mixed wintry precipitation over us at the start, but my early bet is that the storm system is just too strong and easily scours out the cold air. Flooding is more my concern next week, not wintry precpitation.