As the heatwave in the midwest and Northeast begins to ease, a new dangerous heatwave will engulf the Pacific Northwest with temperatures hazardous for at least five days.
Heat alerts blanket the Pacific Northwest, including much of Oregon and Washington state, where temperatures are set to spike to 110 degrees in the days ahead. Northern California will be affected, as well, the atmospheric blowtorch coming as fires torch the Golden State, including the swiftly moving Oak Fire, whose explosive growth has triggered numerous evacuations and a state of emergency.
Daily high temperatures about 10 to 20 degrees above average will persist through at least the end of the workweek, with elevated highs sticking around into the weekend. Several records will be set. Heat index values could reach dangerous levels.
Coastlines will escape the worst of the heat. Interior California, Idaho, Oregon, Washington State, and most of British Columbia will be most at risk of extreme temperatures. This heat wave is not expected to eclipse the 2021 heatwave that killed hundreds of humans and billions of marine animals. But the heat will still be extremely dangerous, particularly for those without air conditioning.
Two processes are at work to drive this fledgling heat wave. First is the stagnation of a heat dome, or ridge of high pressure, to the west of British Columbia over the extreme northeast Pacific. Heat domes bring hot, sinking air and act as a force field that diverts the jet stream north into Canada. That deflects any storminess or inclement weather, fostering predominantly sunny skies. There will also be some downsloping, or air cascading from higher elevations to lower, which results in “adiabatic compression” — as air descends, it heats up and dries out.
The heat wave, while intense, falls shy of the “thousand-year” heat event in June 2021 that brought a high of 108 degrees to Seattle and 116 degrees to Portland. Across the border in Canada, Lytton, B.C., broke the national temperature record three days in a row — and then burned down. Human-induced climate change is a catalyst in pushing otherwise hot weather into extreme and/or record territory.
“You hope there’s some adaptation, given the heat wave we had last year, but when you don’t have that much cooling overnight, it is hard to cool off,” DeFlitch said. “With only a subset of the population here having access to cooling, it can be a challenge in that regard.”
Please leave water outside for wildlife.