UPDATE 9:30 AM, 5/13: Some scattered frost reported in higher elevations and locations west of Roanoke this morning with lows in the 30s common — official low of 40 at Roanoke. A new freeze watch is already posted north of Roanoke for Tuesday morning, with more widespread frost advisories likely to be issued later. A few sprinkles are possible today with a quick-passing disturbance, but no major rain expected. This will be a week of winter-to-summer extremes, with some 80s temperatures later in the week. Full update this evening. END UPDATE
HAPPY MOTHER’S DAY! Expect a sunny day with temperatures rising into the 60s most places in Southwest Virginia. It will be a bit breezy and cool, but dry.
As on Friday, a smattering of severe weather reports occurred Saturday in Virginia (including trees blown down near Thaxton in Bedford County) with storms that at time looked quite impressive at times but were marginal on shear, instability and available moisture. My storm chasing friend and Roanoke resident Chris White of Roanoke photographed some formations with obvious rotation in central Virginia. I stayed closer to home and got a shot of a lowering with a rain shaft (sortakinda looks like a tornado, but it’s not) crossing the Roanoke Valley (was actually with my mother when I shot this, appropriate for the weekend, I suppose). Here’s a nice approaching storm shot from the Valley View area tweeted to me by @Hokie_94. Storm chasing and photography will be very much in our discussions the next few weeks — the first Virginia Tech storm chase trip leaves Blacksburg Tuesday (with Chris White as a co-leader) and the second leaves around Memorial Day (with me as a co-leader)! I think the first-trip group will get some central U.S. severe weather action next weekend.
The cold front that caused the storms has pushed through and a cooler, drier air mass is settling in for the next 3 days or so. We’ve talked a few days about the potential for freezing temperatures and/or frost both Monday morning and Tuesday morning in at least part of our region. The National Weather Service in Blacksburg has issued a freeze watch for Monday morning some counties along the West Virginia border (Craig, Giles, Bland) and along and west of the I-77 corridor (Tazewell, Smyth, Grayson) as well as mountainous counties in its forecast area in West Virginia and North Carolina. I would not be surprised to see freeze watches or warnings eventually issued a little farther east — especially on Tuesday morning — and frost advisories expanded to include most of our region, even into Southside and Piedmont counties, over the next couple of days. Temperatures near or below freezing are likely in most of the area west of Roanoke on Monday and Tuesday mornings, plus some outlying areas and sheltered valleys elsewhere. On Tuesday, the May 14 record lows of 31 at Blacksburg and 37 at Roanoke (both set in 1996) could be in jeopardy. Maximum radiational cooling conditions — clear skies and calm winds for several hours — could also challenge Roanoke’s latest freeze date, which, dating to 1912, was May 11, 1966. Short summary: It would be wide to protect tender outdoor vegetation on Monday and Tuesday mornings, even in the urban areas of Roanoke city.
We’ll shoot back into the 80s by Thursday. As we challenge May records for cold on Tuesday, temperatures may push toward 90 in what has been a very cold Upper Midwest this spring, places like Chicago and Minneapolis. The topsy-turvy, sometimes upside-down spring continues.