Last November, Chris Tangey of Alice Springs Film and Television was filming a wildfire when a small twister touched down, “causing it to build into a spinning flame,” according to Australia’s WPTV.com. Also known as fire whirls, fire devils, or even firenados, these whirlwinds of flame are not really rare, just rarely documented, Jason Forthofer, a mechanical engineer at the U.S. Forest Services’s Missoula Fire Sciences Laboratory in Montana, said in 2010. As Tangey told Northern Territory News, “It sounded like a jet fighter going by, yet there wasn’t a breath of wind where we were” (You Tube video here).
“A fire whirl, colloquially fire devil or fire tornado, is a phenomenon—not commonly captured on camera—in which a fire, under certain conditions (depending on air temperature and currents), acquires a vertical vorticity and forms a whirl, or a tornado-like vertically oriented rotating column of air. Fire whirls may be whirlwinds separated from the flames, either within the burn area or outside it, or a vortex of flame, itself. Most of the largest fire whirls are spawned from wildfires. They form when a warm updraft and convergence from the wildfire are present. They are usually 10-50 meters tall, a few meters wide, and last only a few minutes. However, some can be more than a kilometer tall, contain winds over 160 km/h, and persist for more than 20 minutes…
…Another extreme example of a fire tornado from other than a vegetation fire is the 1923 Great Kantō earthquake in Japan which ignited a large city-sized firestorm and produced a gigantic fire whirl that killed 38,000 in fifteen minutes in the Hifukusho-Ato region of Tokyo. Another example is the numerous large fire whirls (some tornadic) that developed after lightning struck an oil storage facility near San Luis Obispo, California on 7 April 1926, several of which produced significant structural damage well away from the fire, killing two” (source).
Editor’s note: Many thanks to Margaret and Nigel Botting for suggesting this material.
