Chris White is a fellow Virginia Tech Storm Chase co-leader who now lives in Roanoke (previously in Fredericksburg, where he continues to do a weather blog) and does quite a bit of storm chasing in Virginia. Here are some of his experiences with a supercell storm on Friday near the North Carolina-Virginia border that may have spawned at least one tornado.
Roanoke’s high of 57 and low of 34 were each 13 degrees below normal on Sunday. Blacksburg’s high of 54 and low of 29 were each 11 degrees below normal. After another chilly morning with some scattered frost on Monday, we’ll only slowly creep back to normal temperatures the first half of this week, maybe getting kinda close on Tuesday. A big reason for this cool April weather is the jet stream configuration (follow the blue in this 250 millibar chart off the Global Forecast System model for Sunday morning). The jet dips way south to the Gulf of Mexico, which means warmer and more moist air is bottled up south of it, while Canadian air has free range to reach deeply to the south in the central and eastern U.S. Add to that high pressure pushing in a cool east to northeast wind flow against the mountains at the surface, and that’s why the next couple of days will remain cool. A quick-moving cold front approaching from the central U.S. may sweep in just enough warmth and moisture on Wednesday for a seasonably warm day (or even a tad bit warmer, maybe some mid 70s) and then some showers and thunderstorms. That front zips by, we go back to somewhat cooler than normal temperatures for a few days, and then another cold front approaches next weekend. Slowly and surely, this latest incarnation of the unseasonably cool pattern is breaking down, but it’s going to take several days.