UPDATE 11 PM, 6/28: Southwest Virginia has joined the growing heat wave after cool mornings earlier in week
UPDATE 11 PM, 6/28: Roanoke’s high hit 97 on Thursday, the hottest day since last Aug. 4. Blacksburg reached 90, which was only 1 degree off the record June 28 high of 91 set in 1954. Expect very similar temperatures on Friday, perhaps 1-4 degrees warmer — which does make 100 a possibility for Roanoke. Roanoke has not had a 100-degree day in June in 53 years, so that would be quite a noteworthy event if it happens Friday or Saturday. Record highs for June 29 are 101 for Roanoke (1934) and 92 for Blacksburg (1954) . The heat dome that has brought some 110+ temperatures as far east as Arkansas is continuing to expand eastward, and that will continue bring extremely hot air into much of the Southeast, Appalachians and Mid-Atlantic regions. Westerly wind blowing down the eastern slope of the Appalachians will help the heating process. END UPDATE
Meanwhile, Southwest Virginia had another postcard late June day with sunny skies and low humidity. Morning lows were downright chilly in many spots, with lots of 40s west of the Blue Ridge. Blacksburg dipped to 47, only 4 degrees above a record low for June 27, while Roanoke bottomed out at 54, only 5 above a record low for the date. Lynchburg and Danville each set new daily record lows at 50 and 52, respectively. The afternoon warmed up more than the previous day … 80 at Blacksburg, 87 at Roanoke, within a degree of normal at each site … but humidity readings were under 30 percent at times.
Tropical Storm Debby, the cause of the flooding in Florida, has diminished and moved out to sea. But the hot, dry high that is fanning those fires in Colorado and pumping temperatures above 110 in Kansas is expanding eastward, toward us.
After another cool start in the 50s to low 60s, Thursday looks to be the start of a several-days heat wave for Southwest Virginia, with most locations besides the higher ridgetops getting into the 90s, at least the upper 80s. A light westerly wind blowing over the Appalachians, and then compressing and drying as it blows down the eastern slopes, will add to the heat, and may be enough for locations like Roanoke to reach the mid to upper 90s. By Friday through Sunday, a few 100-plus degree readings will be possible, mainly areas below 1,500 feet in elevation, generally from the Roanoke Valley south and east. Humidity will remain low for the first couple of days — it will be a “dry heat,” at least at first — but will slowly build this weekend, though it’s unlikely to become stifling in itself. A few pop-up storms will be possible at times over the weekend, induced by terrain or weak upper-level disturbances, and there is some chance that storms that develop in the Ohio Valley north of the heat dome will form clusters that could slide down the eastern side of the ridge toward our region. Hard-to-predict showers and storms, or the cloudiness produced by the time, often prove to curb our region’s heat waves just a tad. We’ll see if this is the case.
It appears likely the hot pattern will continue through the Fourth of July. After that, there is perhaps some indication of the heat dome shifting back to the northwest and the East emerging into more normal temperatures.