UPDATE 10 AM: Freezing rain advisories have been lifted fof Southwest Virginia as precipitation has ended and temperatures are warming above freezing in most areas. Some patches of ice remain, especially north of Roanoke and along the Blue Ridge, so beware if traveling, especially on rural roads. END UPDATE
Rain and freezing rain began moving into Southwest Virginia late Sunday night, and will continue intermittently during the morning hours. Temperatures will hover near or slightly below freezing in much of our region overnight, rising slowly in some places as milder air above is slowly mixed downward by the precipitation. Patches of ice are likely to develop on streets and sidewalks, more so on trees and exposed objects, though it is not expected to be heavy enough to cause widespread damage to trees or power outages. Eventually, during the day, the wedge of cold air will erode, beginning to the southwest and in higher elevations and working northeast and into lower elevations. Temperatures are expected to warm into the 40s and low 50s, but as you know, wedge situations are often a bit odd and unpredictable when it comes to temperatures. The entire region should be above freezing by noon, most spots by 10 a.m.
This is the start of a wild week of weather that will see temperatures soar into the 60s on Tuesday and perhaps Wednesday too. Heavy rain and gusty winds are possible, maybe even some severe thunderstorms, on Wednesday as a cold front slams into the warmth and extremely strong winds aloft will add some spin to the atmosphere and may work to the surface in some downdrafts. Rainfall amounts of more than an inch may occur across the region this week — with soils now saturated and some lingering snowpack here and there, flooding becomes more of a concern. The front will usher in -a return to cold weather late in the week. Upslope northwesterly winds and possibly some Alberta clipper-like disturbances may trigger some snow showers late in the week. For now, it appears a stronger winter storm system is unlikely to develop late in the week, as a southern-stream disturbance will probably be crushed beneath strong high pressure sinking south with Arctic air. But there may continue to be a window for a possible winter storm to develop several days into the first week of February.
Some of this thinking is reflected in the weekly snow meter, below
0 to 10 chance of getting 1 inch of snow
Roanoke — 3 snowflakes ***Blacksburg — 3 snowflakes ***
Outlook: We’ll see some ice this morning, but no snow. It’s too warm in the layers of the atmosphere above the surface. That warmth works to the ground for Tuesday and Wednesday, when we may some highs in the 60s, with rain and perhaps even thunderstorms on Wednesday. Cold air returns for the late-week period, and there is one piece of atmospheric energy rotating around the newly established southerly jet stream dip that is a bit suspicious. It appears likely this disturbance will get weakened or even crushed out of existence underneath high pressure building cold air southward. I’ve been burned two weeks in a row going with a “4,” but this situation looks a little less likely to produce an inch or more of snow than the last two, so I went a bit lower than even that. Keep it in mind though if you see snow forecasts start to increase late in the week. The window for potential snow may continue into the following week, beyond the time frame of this snow meter.
Looking back: I knew when we started this that iffy late-week systems would be the toughest. I’m on a 2-week losing streak after again going 4 flakes on the snow meter and having an inch fall (1.5 at Roanoke, 1.9 at Blacksburg) in Friday’s light snow event. I mentioned the possibility in the outlook, again, but the rules are, less than 5 flakes and it snows an inch, I take an “L.”
Current records: 6-2 for Roanoke, 5-3 for Blacksburg.