Fire whirl captured on video during Tennant fire as crews battle multiple blazes across California

Not only are California's firefighters up against severe heat and extreme dryness as they battle multiple blazes across the state, but extreme weather conditions have also created fire-induced tornadoes.

The U.S. Forest Service captured video of a fire whirl — a "spinning vortex column of ascending hot air and gases rising from a fire" — on June 29 at the Tennant fire in Klamath National Forest, near the Oregon border.

Fire whirls carry aloft smoke, debris and flames, the Forest Service said.

In the astonishing video, thick black smoke quickly gathers and spins near flames, almost completely obscuring a rescue truck in the distance.

The fire whirl was strong enough to be picked up on the National Weather Service's radar, meteorologist Charles Smith said from Medford.

Smith couldn't say how long the visible whirl lasted, but noted that the radar captured as much as 30 minutes of rotation.

Fire whirls aren't unprecedented, he said, but they're "on the rarer side."

Capt. Tom Stokesberry with the Tennant fire's incident team said it was one of the first times such a whirl has registered on radar and been captured on video, and noted that some trees were uprooted by the tornado.

As of Thursday morning, the Tennant fire had seared through 10,580 acres and was 81% contained, Stokesberry said, adding that the fire crews had "turned a corner on the blaze."

Still, the whirl is yet another sign of the dangerous weather conditions threatening the parched state, where several other substantial wildfires have ignited.

The 25,000-acre Lava fire in Shasta-Trinity National Forest — the state's largest fire of the year so far — is now 70% contained, officials said.

The Salt fire, also in Shasta-Trinity, was at 12,644 acres and 35% containment Thursday morning, according to the Forest Service. That fire ignited June 30 and went on to destroy more than two dozen homes.

Farther south, the two-fire Beckwourth Complex in Plumas County continues to sear through wildlands. The larger of the two blazes, the Sugar fire, nearly quadrupled in size overnight, incident spokeswoman Phyllis Ashmead said, swelling from about 3,000 acres to 11,799 acres Thursday morning. It is 20% contained.

"Very warm temperatures and southwest winds kind of lined up with the terrain and the vegetation," Ashmead said, "so it's just very primed for fire."

Crews were working hard Thursday morning to take advantage of calmer conditions before 30-mph gusts return in the afternoon, she said.

The Plumas County Sheriff's Office has issued additional mandatory evacuation orders for Frenchman Lake, including all campgrounds and residents around the lake. Those orders were in addition to previously issued evacuation orders for residents from Beckwourth Genesee Road to Harrison Ranch Road.

The smaller of the two Beckwourth fires, the Dotta fire, is at 670 acres and is 76% contained, Ashmead said.

Meanwhile, the 868-acre Tumbleweed fire in northern Los Angeles County is nearly fully contained, the L.A. County Fire Department said. All road closures and recreation area evacuations have been lifted.