The Dixie fire generates a vortex of fire, a cloud of pyrocumulonimbus

Almost a month after the ignition, the monstrous Dixie fire in northern California destroyed nearly 900 structures and continues to exhibit extreme behavior, officials said.

The blaze, which ravaged 487,764 acres in four counties north of Sacramento, continues to generate its own climate.

At around midnight Monday, an explosive thunderstorm cloud rose about 40,000 feet above the eastern portion of the fire.

the pyrocumulonimbus cloud was so intense that it set off lightning bolts, along with flaming vortices known as vortices of fire, said Rich Thompson, a National Weather Service incident meteorologist for the Dixie Fire.

A great whirlwind captured by infrared camera shows a fine tendril winding above the rest of the flames. Thompson estimates he climbed 300 to 400 feet above an area west of Antelope Lake, where evacuations were ordered this week.

“It’s a sign to let people know that this fire still has a lot of potential,” Thompson said. “It’s actually something very impressive to watch.”

A vortex of fire – sometimes likened to a tornado – is generated as hot air rises and begins to spin. Spiraling, it can collect ash, smoke and embers and form a tight, spinning vortex, like the one seen Monday night, Thompson said. The spinning action can “throw those embers through the lines of fire, which can cause really big control issues,” he added.

the second largest fire in California history, the Dixie fire burned at least 893 homes and commercial buildings and threatened more than 16,000 more, according to the latest incident report.

Crews have made progress on the fire in recent days and containment has risen to 25%, from 21% on Monday.

The blaze, which burns in Plumas, Butte, Tehama and Lassen counties, razed the remote Sierra town of Greenville last week and destroyed homes in Canyondam, Indian Falls Canyon, Chester and elsewhere, said Monday evening Plumas County Sheriff Todd Johns.

Many people cannot return to their communities due to fire threats and evacuation orders.

“Many of our friends and neighbors have lost everything, and I know that for these people the process of healing and recovery will begin when they are able to see the damage to their property,” Johns said.

Authorities have issued evacuation orders for the Antelope Lake and Janesville area to the north, and firefighters are conducting proactive structural protection operations in those areas, said Tim Jones, spokesperson for the California Department of Forestry and fire protection.

Pacific Gas & Electric said its equipment may have sparked the Dixie fire, which broke out on July 13 near the utility powerhouse in Feather River Canyon, as well as another fire that later merged with Dixie.

As firefighters begin to progress on the blaze, conditions this week are expected to worsen.

Heavy smoke that had converged over the blaze moderated the temperatures and behavior of the fire, officials said; the blanket gave the crews time to progress in the fight against the fire. But the smoke began to clear on Monday, paving the way for another spike in temperatures and falling humidity levels.

The weather is part of the drought and heat, fueled by climate change, that has dried up the western United States and spurred rapid growth in fires.

Temperatures in the fire zone hovered in the 90s on Tuesday and are expected to reach 100 on Wednesday and Thursday. Humidity could drop in teens during the day this week, with potentially little to no recovery at night, forecasters said.

Also complicating firefighting efforts: Afternoon winds are expected, with southwesterly gusts up to 20 mph. And from Thursday, there is a risk of isolated thunderstorms that bring the possibility of dry lighting and irregular winds.

“Firefighters are still on high alert,” Thompson said.

Much of the southern and southwestern parts of the blaze are “buttoned up,” but there is room for significant growth in the north and northeast, he said.

Some areas along the eastern edge of the blaze are in areas of burn scars, which provide some natural protection as vegetation has been thinned there by previous fires, Thompson said.

Dixie is one of 96 fires raging in the West, said Rocky Opliger, an incident commander with the California 4 Interagency Response Team. More than 25,000 firefighters are deployed to fight the blazes. , including nearly 6,000 assigned to Dixie alone, he said.

West of the Dixie Fire, the lightning-triggered monument fire continues to spread, with little containment, across Trinity County. The blaze, which started July 30 near Monument Peak, had reached nearly 58,000 acres and was 3% contained on Tuesday, according to the latest incident report.