A swirling, destructive plume of fire and smoke that formed last week during a deadly California wildfire grew into an exceedingly rare "fire whirl" as powerful as an intense tornado, meteorologists said Thursday, in what may have been the strongest such event ever recorded.
The fire whirl formed on July 26 as the Carr fire exploded into the city of Redding, killing six people and charring more than 125,000 acres. The phenomenon was captured on video as residents fled the ominous, towering vortex of smoke and flame spinning into residential neighborhoods.
As the smoke cleared, crews in the area discovered massive amounts of wind-related destruction including uprooted trees, damaged roofs, and high-voltage power lines that had been ripped down. The fire remains only 35% contained, but earlier this week National Weather Service teams began surveying the damage and on Thursday announced that "preliminary indicators" suggested maximum wind speeds achieved by the fire whirl were in excess of 143 mph.
If those results hold, it would mean the fire whirl was as powerful as an EF-3 tornado on the Enhanced Fujita Scale, a phenomenon that forecasters classify as severe and which can cause major damage on the ground. Such destructive tornadoes are more commonly found in the Midwest and Plains states and are associated with severe thunderstorms.
Daniel Swain, a climate scientist at the University of Southern California, Los Angeles, said that if the fire whirl's wind speeds are ultimately confirmed it "could end up being the strongest tornado feature in California history."
While powerful fire whirls have been documented before, Craig Clements, the director of San Jose State University's Fire Weather Research Laboratory, said the vortex of fire that hit Redding may have been the strongest ever recorded.
"This is historic in the US," he said. "This might be the strongest fire-induced tornado-like circulation ever recorded."
Hannah Chandler, a meteorologist at the National Weather Service Sacramento office, said the conditions observed in the Carr fire were uncommon and exceeded even the expectations of experts who had been observing photos of the damage.
"That’s significantly stronger than what we were expecting after the first reports came in," Chandler said of the tornado-like wind speeds.
Only a few documented fire whirls have come close to the strength of the one generated by the Carr fire, the strongest occurring in January 2003 during a devastating wildfire in Australia. After surveying damage from that event, researchers discovered snapped trees, damaged buildings, and a two-ton police car that had been picked up and thrown into a storm drain.
From the damage, researchers concluded that the tornado was at least EF-2 strength, though at its peak it may have reached EF-3 intensity.
Fire whirls are not technically tornadoes because they form under different atmospheric conditions. Smaller and weaker whirls are common during wildland blazes and often appear like dust devils made of flame and ash, spinning through fire zones.
But the sheer intensity of the Carr fire made the destructive phenomenon unlike any run-of-the-mill fire whirl, Swain said.
"It had the intensity of a regular old tornado but it had the formation mechanism of what you’d see on a large fire," he said. "It shared more characteristics with a traditional tornado than we’d expect to see."
While fire whirls are typically short-lived, spinning themselves out after a few seconds, Clements said that the Carr fire vortex was unique because it appears to have continued for more than an hour.
The damage caused by the tornado-like whirl astonished fire officials who battled the blaze. Cal Fire Deputy Chief Bret Gouvea said it was "incredibly unique to have fire tornado activity of that magnitude."
"Roofs were ripped off houses," he said. "That was an F3, F4 tornado that swept through with fire inside of it. The speed in which it traveled was unprecedented for us. It traveled 10 miles in a matter of hours."
Greg Bertelli, division chief for Lake County, said it "took things to the next level."
"I have never seen something move with that much speed that was not a result of a wind-driven event," he continued.
Experts who spoke to BuzzFeed News stressed that the fire whirl was the result of local weather and extreme fire conditions, and that it's difficult to draw a direct link between it and larger trends like climate change. However, officials have for years warned that California and the West more broadly are likely to face more intense wildfires and long fire seasons in the future, with California Gov. Jerry Brown describing the situation as "the new normal" in December and just last week predicting worsening conditions going forward.
That trend may have a very real human cost, which the West will have to grapple with in the near future.
"This vortex was not just a curiosity; it burned people’s homes and it killed people," Swain said. "The fact that we’re seeing wildfires right now in California that are moving faster than even people who are doing all the right things can escape them is scary."