Pyrocumulonimbus Clouds

The Bootleg Fire in Oregon has spawned tornadoes and has generated plumes of smoke that rise to the altitude of jet aircraft flightpaths. 

Image from hdnux.com

The rising currents of air create clouds resembling cumulonimbus formations, but because they're generated by fire, they're known as pyrocumulonimbus clouds.

According to the New York Times, the pyrocumulonimbus cloud over the Bootleg Fire is "similar to a thunderhead. 'It likely reached an altitude of about 45,000 feet,' said Neil Lareau, who studies wildfire behavior at the University of Nevada, Reno. Like a thunderhead, the huge cloud spawned lightning strikes, worrying firefighters because of their potential to start new fires."

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New York Times: "How Bad Is the Bootleg Fire? It’s Generating Its Own Weather."