The intense hot spell that finally began waning Monday night echoed the memorable heat wave that embroiled the Pacific Northwest in June of last summer.
Both were widespread, intense and long-lasting. And both were caused by an atmospheric condition called a heat dome, when a large ridge of high pressure traps heat over a region like a lid on a pot. What’s more, the two heat domes behaved similarly. Instead of being centered above the Desert Southwest and extending into the Pacific Northwest, each dome was solidly parked over the northeast Pacific Ocean, to the west of us and British Columbia.
Also, both heat domes languished over a single location for seven days, compared to the average of three to five days being centered over one location. 2021’s heat wave primarily roasted Washington, Oregon, Idaho and southwestern Canada from June 26-July 2. This year’s heat wave persisted from July 26-Aug. 1 and impacted the same areas.
Yes, the two heat events shared a lot in common, but there’s a standout difference. Last summer’s hot spell was more brutal and freakish – a weather episode that killed at least 125 people in Washington and 115 in Oregon, and which had previously seemed unattainable in this part of the world. It was “the most anomalous extreme heat event ever observed on earth since records began two centuries ago,” Meteorologist Christopher Burt, author of the book “Extreme Weather,” wrote in a Facebook post.
Not only were heat records broken last summer, they were obliterated. Seattle, 108 degrees; Walla Walla, 116; Yakima, 113: Spokane, 109. Northwest of the Tri-Cities, it soared to a sizzling 120 degrees in Hanford – the hottest temperature recorded in Washington state history.
Not that this recent heat wave was a walk in the park. More like a slog through a furnace room. The Inland Northwest’s high temperatures include 102 degrees in Spokane, 109 in Yakima and 112 in the Tri-Cities. Also noteworthy is that the Tri-Cities saw six straight days with temperatures above 105 degrees. As for consecutive days with temperatures over 100 degrees, Yakima had eight and Spokane saw four.
While a trough of low pressure was expected to bring temperatures into the low to mid-80s Thursday and Friday, temperatures are predicted to rise to the upper 80s on Saturday and then creep back into the 90s.
Nic Loyd is a meteorologist in Washington state. Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek. Contact: firstname.lastname@example.org.
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