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Another intense heat wave to roast Western U.S., southwest Canada

Temperatures 20 degrees above normal could bring record-challenging heat to the West once again

Forest fires are raging across western Canada as a record-breaking heat wave in the region sparked a surge in lightning strikes. (Video: Reuters)
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Last week, Lytton, a small town in British Columbia, Canada, broke its nation’s all-time temperature reading three days in a row as temperatures soared as high as 121 degrees. Days later, the village largely burned to the ground as extreme wildfires spewed smoke and ash 55,000 feet into the sky.

‘Hard to comprehend’: Experts react to record 121 degrees in Canada

Now, southwest Canada and much of the western United States are bracing for another bout of exceptional heat amid a pattern that could once again place records in jeopardy. Death Valley, Calif., might spike to 130 degrees.

Temperatures up to 25 degrees above average could dominate most of the West this weekend into next week, with little relief in sight for quite some time. Odds favor anomalously hot and dry conditions to prevail into the fall.

On Tuesday, weather models were hinting that a building ridge of high pressure over the West, colloquially known as a summertime “heat dome,” would become established over the Four Corners region later in the week. By Saturday, it will be reinforced by a secondary such system passing through west central Canada, the two systems’ synergy resulting in widespread unusual to record temperatures.

Excessive heat watches blanket much of southeast California in the Mojave Desert, as well as southern Nevada and adjacent northwest Arizona. Heat advisories and excessive heat warnings extend through the Great Basin northward into interior northern California, western Utah, southeast Oregon and southern Idaho.

“This warning is reserved for only the hottest days of the year and is issued when temperatures are expected to rise to dangerous levels,” wrote the National Weather Service office in Flagstaff, Ariz. Between Wednesday and Saturday, high temperatures below 4,000 feet elevation in northwest Arizona, particularly in the canyons, could range between 110 and 117 degrees.

Death Valley will flirt with record temperatures, expected to climb into the upper 120s to near 130 degrees. It is possible that temperatures will not drop the century mark from Wednesday morning to the middle of next week, with overnight lows around or above 100 degrees. On Sunday, the afternoon high could nick 130, which would match the highest temperature recorded there or anywhere on the planet in decades.

The heat will not just fester in the desert — it will scorch populous areas already gripped by extreme to exceptional drought. More than 25 million Americans will endure triple-digit heat over the coming week, many of whom reside in California’s Central Valley.

Highs in much of the San Joaquin Valley will top 95 degrees on Wednesday and Thursday. Highs between 100 and 105 are likely Friday before the heat ramps up markedly toward the weekend. By Saturday, most of the Golden State’s interior valleys will be looking at highs approaching 110 degrees.

Redding, Calif., could see highs of 110 degrees or greater from Friday into at least next week; overnight lows, meanwhile, will offer next to no respite from the brutal temperatures.

“Little to no overnight relief is expected as lows may only cool into the upper 60s to low 80s,” wrote the Weather Service office in Sacramento. Sacramento itself will likely hit 104 degrees for the high both Saturday and Sunday.

Needles, Calif., along Interstate 40 at the Arizona border, will crest above 115 degrees every day in the coming week, with highs around 120 degrees expected Saturday.

“Heat like this happens rarely,” wrote the Weather Service in Hanford, Calif. “Very high heat risk to everyone.”

The heat will extend all the way into Canada on Saturday, with highs around 100 bleeding into British Columbia. Medford, Ore., will see a high of 103 degrees; Boise, Idaho, could jump to 102, and Las Vegas will sizzle at 115 degrees. Areas closer to the coast, such as Seattle and Portland, will remain in the 80s.

Extended weather models suggest that high pressure will remain in control and bring significant warmth over the next two weeks. As it stands, the intensity of the heat wave this weekend is predicted to be comparable to what once may have been a once in five-year or once in 10-year event for some areas. The magnitude and frequency of heat extremes, like the unprecedented outbreak of high temperatures blamed for hundreds of excess deaths in Canada and the Pacific Northwest last week, is increasingly due to human-induced climate change.

Climate change has gotten deadly. It will get worse.

Drought, spurred in large part by the rising temperatures, is playing a role, too. The parched landscape and ceaselessly dry conditions desiccating the West have made it easier for temperatures to overachieve too. That in turn evaporates more moisture from the environment, leading to a seemingly inescapable cycle.

It also portends a potentially devastating wildfire season ahead.

What questions do you have about the heat wave? Ask The Post.