UPDATE 10:45 PM:
It appears precipitation may be a bit slower to move in Tuesday, perhaps after sunrise. (Has arrived, blog update above) Most forecast guidance points to the bulk of snow passing north and west of the Roanoke and New River valleys — through eastern West Virginia, across the I-64 corridor toward D.C. — but enough uncertainty remains to keep an eye on how it develops in the morning. END UPDATE
You can think of the system moving through Tuesday morning as the third episode of the winter weather trilogy — Sunday morning’s patchy ice and sleet, Sunday night/Monday morning’s general freezing rain event, and whatever happens Tuesday morning. The last piece of energy will trigger a low that squirts northeastward over the Carolinas on Tuesday, strengthening a bit as it passes us to the east and southeast. This will throw moisture north and west, just as new cold air arrives in Virginia. It’s timed much better for the northern half of Virginia to get a substantial snow — perhaps 3 to 5 inches in many locations, maybe more for some. But it does appear the cold air will slide in just in time for some snow and sleet in Southwest Virginia, primarily west and northwest of Roanoke. The Roanoke Valley is quite literally the pivot point on the majority of model runs, on the bubble between a couple or three inches of snow and not much at all. (Would you expect anything different than that?) A mix of rain and sleet is likely to begin in the wee hours of Monday morning, perhaps some pockets of freezing rain mainly west of Roanoke, and eventually go over to snow as atmospheric layers from cloud to ground cool to below freezing. Higher elevations of the Blue Ridge south of Roanoke may also go to snow a little earlier than lower elevations in the Roanoke Valley and eastward. Whatever snow occurs could be heavy for a bit, but shouldn’t last long, likely over by
noon mid-afternoon in most locations that sees snow.
The rest of the work week looks cold but dry. There is a potential precipitation system to deal with over the weekend, and it looks as if might be cold enough for at least some of it to be wintry. More on that later.