West bakes in another weekend of intense heat as wildfires spread

Heat waves have already engulfed western states this summer, including one in June that left more than 100 dead in the Pacific Northwest. Now, a “heat dome” is expected to bring sweltering temperatures over the weekend and early next week to the Northern Rockies and the High Plains, including parts of Idaho, Montana, L ‘Utah and Wyoming, according to an AccuWeather forecast.

It will be “dangerously hot, especially for those who are more vulnerable to the heat,” said John Wetenkamp, ​​scientific and operational manager of the National Weather Service in Billings, Mont., Who issued an excessive heat warning for noon. Saturday. until late Thursday.

July has already brought some scorching days in parts of Montana, he said, but residents are now facing a succession. Temperatures in Billings soared on Saturday and could reach 102 degrees Sunday and 105 degrees Monday, potentially breaking a record set in 1960.

“There is really no relief in sight for the next few days,” Wetenkamp said.

There was, however, a chance that smoke from nearby wildfires could reduce some of the heat, according to AccuWeather.

Meanwhile, officials in several states said long-term drought, low humidity and heat made it more difficult to manage the fires.

The largest fire currently burning in the United States, the Bootleg Fire in south-central Oregon, was 22% contained on Saturday morning after increasing by 40,000 acres on Friday night and spanned 281,208 acres, Oregon Forest Department spokesperson Marcus Kauffman said.

Temperatures in the Bootleg Fire area are about 5 to 10 degrees above normal, although they are still not as high as they were a few weeks ago, said Misty Firmin, a meteorologist at the National Weather Service in Medford, Oregon.

The safety concern is not so much the hot weather as the low humidity, dry and gusty winds and the vegetation much drier than normal in mid-July.

“Tinder is dry,” Kauffman of the Oregon Forestry Department said of grass, shrubs, brush and trees. “If there is a spark that shoots out of this fire, it will ignite.”

Fires generate their own extreme weather conditions. The US Naval Research Laboratory said on Friday that the current wildfires generate a record number of pyrocumulonimbus clouds – created by intense heat pulling air quickly up a fire.

This phenomenon occurred in the Bootleg Fire, pulling embers, branches, leaves and particles upward in a column that then descends with a force that intensifies the fire, Kauffman said.

Nationally, the current fire season has so far been comparable to that of recent years. More than 70 large active fires have burned nearly a million acres in the West.

Washington Gov. Jay Inslee declared a state of emergency in 19 counties on Friday, saying the unprecedented heat there caused failures on roads, bridge joints and other types of infrastructure.

In California, Governor Gavin Newsom declared a state of emergency in three northern California counties that suffered evacuations and damage to critical infrastructure from the Beckwourth Complex fire, fires caused by lightning strikes that , Saturday, totaled 105,348 acres and was 70% contained.

In Lassen County, which is included in the emergency order, organizers were working on Saturday to prepare for the county fair. After a cancellation last year, this year’s slogan is “Back in the Saddle Again”.

Those evacuated by firefighters who were sheltering at the fairgrounds have been moved to Lassen Community College, said Holly Mueller, vice chair of the fair’s advisory board. “Everyone is on the bridge for the fair to take place,” she said. “Just so that we can bring the community together.”

A sign that the drought in the West is worsening, the US Bureau of Reclamation said on Friday it is taking the unprecedented step of releasing more water from reservoirs upstream of Lake Powell to help keep its level high enough for production. electricity.

The lake, which straddles the Arizona-Utah border, has fallen to one-third of its capacity during drought conditions for much of the past two decades.

Lake Powell is the largest reservoir of water in the Colorado River after Nevada’s Lake Mead, and the Glen Canyon Dam turbines generate electricity in the southwest. According to the federal agency’s forecast released on Friday, there is a 79% chance that Lake Powell will fall below a threshold below which a power outage could occur.

A total of 181,000 additional acre-feet of water will be released through the end of the year from the Flaming Gorge Reservoir in Wyoming, the Blue Mesa Reservoir in Colorado and the Navajo Reservoir in New Mexico to elevate Lake Powell by 3 feet.

“We were hoping that we would never have to go this route, but now we have to,” Wayne Pullan, regional manager of the Salt Lake City office, said Friday in a video briefing with the media.

—Jim Carlton contributed to this article.

Write to Jennifer Levitz at [email protected]