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Records torched as western U.S. sizzles amid major heat wave

Death Valley, Calif., could hit 132 degrees Saturday after soaring to 130 on Friday, the highest temperature since 1931

Forecast highs Saturday from the National Weather Service. Boxed values are records. (WeatherBell)

Barely a week and a half has passed since an unprecedented “thousand year” heat wave killed hundreds in the Pacific Northwest and British Columbia, and established a new Canadian record high temperature at 121 degrees. Now a new heat wave is scorching the West, with highs some 20 degrees or more above average set to catapult readings into record territory.

Over the weekend, more than 28 million Americans can expect to find themselves enduring triple-digit heat, the majority residing in Arizona, Nevada and California’s Central Valley. Even interior Washington state could see some 100-degree temperatures, which could spill across the Canadian border.

Photos: Another heat wave builds across the western U.S.

Excessive-heat warnings blanket most of California, Nevada, and western Utah and Arizona, and even southeast Oregon and southern Idaho. A heat advisory traces out a zone in Washington state that juts up against Canada. Glasgow, Mont., is under an excessive-heat watch, where temperatures could top 100 degrees Sunday.

Historically significant heat began Friday.

Grand Junction, Colo., reached an all-time high of 107 degrees.

Western states braced for more scorching weather this weekend after the hottest month of June on record in the United States killed scores of people. (Video: Reuters)

Death Valley, Calif., arguably the epicenter of the toasty temperature outbreak, hit 130 degrees, matching the warmest temperature observed anywhere on Earth since July 7, 1931, when Kebili, Tunisia, soared to 131 degrees. However, according to some climatologists, that reading was doubtful — as was the planet’s all-time record of 134 observed in Death Valley on July 10, 1913 — meaning Friday’s high in Death Valley may have tied the record for Earth’s hottest reliably measured temperature.

Death Valley soars to 130 degrees, matching Earth’s highest temperature in at least 90 years

Death Valley also hit 130 degrees on Aug. 16, 2020. There is a chance it will be even hotter on Saturday, with a high of around 132 possible.

Fortunately, Death Valley is sparsely populated — but the same can’t be said for California’s Central Valley, one of the nation’s most densely populated strips of real estate, where widespread highs will leap past 110 degrees. Saturday is slated to be the hottest of the bunch, with a brief easing in temperatures likely mid- to late next week.

How hot will it get?

Redding, Calif., at the northern end of the San Joaquin Valley, is eyeing highs of around 115 degrees both weekend days. That could flirt with daily records, but should hold short of the all-time record 118-degree reading set on July 20, 1988.

Sacramento is forecast to hit 112 degrees on Saturday and 110 on Sunday, tying daily records for both days. The city’s all-time record is 114 degrees. It got to 109 degrees downtown on Friday, a daily record.

A number of cities could come close to smashing all-time readings, like Fresno, where the record 115 degrees “is in reach” on Sunday, according to the local National Weather Service office. The “dangerously hot conditions” could “significantly increase the potential for heat related illnesses.”

Even Las Vegas, a city accustomed to grueling heat in an unforgiving desert climate, is likely to tie or break its all-time record Saturday. McCarran Airport has never recorded a temperature above 117 degrees, but it came close Friday: The high peaked at 116, a record for the date. The 117 mark, last reached on June 20, 2017, is very much in jeopardy over the weekend.

The morning weather balloon launch Saturday from Las Vegas measured temperatures of 75 degrees as high as 9,000 feet above the ground. Imagine climbing a mountain 1½ miles high and still being able to wear short sleeves! Temperatures ordinarily drop markedly as one ascends higher into the atmosphere.

The Weather Service in Las Vegas said the weather balloon sampled “about as intense of a … heat dome” as would be found in mid-latitudes.

The science of heat domes and how drought and climate change make them worse

Particularly impressive amid the episode of heat, which in some areas is a once-in-20-year event, is the magnitude of the warm overnight lows. Many locales aren’t dropping below 80 degrees at night, the lack of an adequate cooling period providing little respite for the elderly and other vulnerable groups without access to cooling. That opportunity for nocturnal cooling is vital in maintaining a safe body temperature. Heat is the leading weather-related killer in the United States and most of Europe.

“Regardless of the outcomes to the record books, the heat through the weekend into the early part of next week is DANGEROUS,” cautioned the Weather Service in Las Vegas. “Continue to take extreme precautions to minimize your exposure to the heat.”

In Las Vegas, the temperature won’t drop below 90 degrees until Tuesday night. On Friday evening at 10 p.m., the temperature was still 99 degrees in Chico, Calif., and 94 in Redding.

Areas along California’s coastline will elude the heat. San Diego is predicted to see highs in the comfortable mid-70s through the weekend. The San Francisco Bay area will also see temperatures mostly in the 70s. Los Angeles will be in the 80s. But temperatures will heat up rapidly in the interior valleys and lower mountains adjacent to these population centers.

A vicious feedback with drought

The heat in and of itself, catalyzed by human-induced climate change, is economically disruptive and, in many instances, deadly, but also has compounding effects — namely in the form of drought and wildfire impacts. The western United States is already years into a potentially disastrous “megadrought,” with 60 percent of the landscape experiencing an “extreme” or “exceptional” drought — the two most severe categories.

Reservoirs are drying up as consequences of the Western drought worsen

According to the U.S. Drought Monitor, that means “water shortages are widespread, surface water is depleted [and] federal irrigation water deliveries are extremely low.”

That drought will continue to dry the soil and make it easier for the air to heat up — in turn desiccating the landscape even further. And with the autumn fire season soon to roll around, it stands to reason that the months ahead could be troublesome.