Monday certainly didn’t live up to its potential for rainfall, not that there was a lot expected, but most of the showers either went north or south of most of Southwest Virginia, and those that appeared to be headed our way from the west diminished crossing the mountains this evening. Roanoke ended up get 0.21 total for 2 days through 11 p.m. and Blacksburg right on a quarter of an inch, most of it on Sunday at both sites. There might be a few more showers overnight — even some snowflakes by morning, mainly higher elevations west of Roanoke — but for the most part this little episode of dampness is over. And the drought continues.
Get ready to ride the temperature rollercoaster the next few days. The cold front passing through overnight is hardly worthy of that title, as we’ll be right back in the 50s during the day Tuesday and possibly some 60s on Wednesday. It does look very likely that the next cold front will be fully worthy of the title, slamming through late Thursday, possibly kicking up some showers and maybe even a few rumbles of thunder ahead of it. Behind it, we’ll get a true shot of Arctic air from the core of a very cold air mass sitting over Canada. Even with sunshine it will struggle to make 40 in much of Southwest Virginia on Friday, with some 50+ mph wind gusts possible. Those northwest winds will trigger snow squalls in West Virginia’ s higher terrain, as is typical from the upslope flow squeezing out Great Lakes moisture in even colder air just above the surface, and a few inches may occur in the common upslope belts, even into the far western fringe of Virginia and the I-77 corridor. You know if your location typically gets upslope snow squalls on northwest winds — expect to see some white ground if you’re in one of those spots. At lower elevations and farther east, don’t be surprised to some snow showers scattering in the breeze in the New River Valley, along the Blue Ridge, and perhaps even briefly into the Roanoke Valley and western Piedmont or Southside by Friday morning.
The guidance has bounced around a little bit, but it now looks as if cold temperatures will hang on through Christmas, though it will be mostly dry. It is also becoming more evident that a large storm system will likely develop and affect some portion — potentially, a very large part — of the central and eastern U.S. a couple of days after Christmas or so. While the forecast models are bouncing around trying to locate where this storm will go, there is some reason to think a traffic jam of weather systems in eastern Canada may be able to cause a more southerly track than the storm systems we’ve seen so far. That would increase the chance of significant precipitation — wet or frozen — in Southwest Virginia. But it’s too far out for those details to be extremely clear. Something to keep on the backburner as we watch the approaching Arctic air mass this week — which will trigger an Upper Midwest snowstorm that will break record snowless streaks that date to early March in many of the bigger cities there.