There was patchy frost and even snow this past week in western Virginia, but mostly, several chilly days that didn't feel much like May. Next weekend won't feel like May either, but more like July.
Clouds and showers over the first half week mark the transition from "blackberry winter" to what will essentially be a summer preview, if not an early arrival of summer, by the weekend. 30s and 40s lows last week will be forgotten as highs soar into the lower 90s, possibly as early as Friday, in the lower elevations of our region, likely including Roanoke city.
Early this week, a warm front gradually lifts northward, with Gulf of Mexico moisture overrunning cooler air wedged against the mountains at the surface. This will result in showery weather for the first half of the week, especially on Monday.
Though total rainfall for the year is near normal, our region is generally about 3 inches behind normal for meteorological spring, or the time since March 1, with just a couple weeks left. This week's showers will not catch us up, likely well under an inch for most, but will provide some needed moisture for growing things. (A year ago this coming week, we were about to hit 5 days of almost constant rain with a "cut-off low" that totaled 8-12 inches in many locations.)
As the first half of the week moves along, rain will tend to become more scattered, but could get a little more rumbly as temperatures slowly warm and the air becomes a bit more unstable. A widespread severe storms risk is not expected in our region -- but there could be many days of that in the central U.S. with the developing pattern.
The same high pressure system that is wedging some cooler air down to meet the moisture early in the week will intensity, grow and stall over our region and end up being what brings several days of sunny, warm to hot and mostly dry weather later this week and through the weekend.
Roanoke has yet to hit 90 degree thus far in 2021 -- it hit 88 on April 27 and 28. If Roanoke's first 90-degree day happens to be Friday, that would be May 21, just two days later than the average first 90-degree day over the past 109 years, May 16. It didn't happen till June 3 last year, but we ran off a record 29 in a row in a July, so earliness or lateness of the first 90-degree day has little to do with how the subsequent summer plays out.
From this distance it looks likely that Friday, Saturday or Sunday will be that first 90+ of 2021 in the Star City, but there a a few days for something to alter this, such as having more moisture and more showers and storms bubble in that heat. For now, it looks hot and mostly dry going into the coming weekend.