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‘Heat dome’ in western US, Canada brings scorching temperatures

The scorching weather wilting people and pets alike in Washington state, Oregon and the rest of the Pacific Northwest — where temperatures this week broke all-time highs as they soared well past 100 degrees — is being triggered by a meteorological phenomenon known as a “heat dome.”

Seattle hit 108 degrees Fahrenheit by late Monday — well above Sunday’s all-time high of 104 degrees. Portland reached 116 degrees after hitting records of 108 on Saturday and 112 on Sunday, officials said.

In Oregon’s capital of Salem, temperatures reached a mind-melting 117 degrees, the hottest since record-keeping began in the 1890s.

Mother Nature offered a small measure of relief Tuesday, with temps rising to “just” into the 90s across the western part of the state and at or around 100 in some of the Cascade Foothills.

The PNW grilling was attributed to a massive “heat dome,” which occurs when “strong, high-pressure atmospheric conditions combine with influences from La Niña, creating vast areas of sweltering heat that gets trapped under the high-pressure ‘dome,’” according to the National Oceanic and Atmospheric Administration.

Temperatures in the Pacific Northwest this week broke all-time highs as they soared well past 100 degrees. Mathieu Lewis-Rolland/Sipa USA

The blistering heat was caused by two pressure systems, one emanating from the Aleutian Islands in Alaska and the other from James Bay and Hudson Bay in Canada, according to National Weather Service meteorologist Richard Bann, the Guardian reported.

“The Pacific Northwest got caught in a region where a series of feedbacks set up these very warm temperatures — no, hot temperatures — with very little cloud cover and very warm temperatures at night too,” Bann told the news outlet.

The “dome” term refers to the idea that this kind of heat extends high into the atmosphere and isn’t just a thin layer — and that it can have an impact on pressure and wind patterns, according to the Guardian.

People rest at the Oregon Convention Center cooling station in Portland, Oregon. Kathryn Elsesser/AFP/Getty Images

“That is important here in the Pacific Northwest with the present event because it has served to essentially shut off the flow of cool marine air off of the Pacific into the land area,” Washington state climatologist Nick Bond told the paper.

“It blows my mind that we could get the temperatures that we’re observing here in the Pacific Northwest, especially on the west sides of the Cascades that [have] that proximity to the ocean, that it could get that hot for so many days in a row,” he said.

“I would have been willing to guess something like that in the middle of the century, in the latter part of the century,” Bond added.

Dick’s Drive-In in Seattle, which is not air conditioned, closed early Sunday and all day Monday due to excessive heat. Ted S. Warren/AP

The Seattle Parks Department closed one indoor community pool after the air inside became too hot — leaving Stanlie James, who recently relocated from Arizona, to search for somewhere else to cool off.

She said she doesn’t have air conditioning at her condo.

“Part of the reason I moved here was not only to be near my daughter, but also to come in the summer to have relief from Arizona heat,” James said. “And I seem to have brought it with me. So I’m not real thrilled.”

With Post wires