Earth Notes: Fire whirls and tornadoes
Fire and strong winds can be a destructive and deadly combination in the forest. Extreme heat and turbulence can create fire whirls and fire tornadoes.
The two terms are often used interchangeably, but meteorologists and fire scientists distinguish between them. The more common fire whirl is a spinning vortex generated by wind shear, complex terrain, and other features. A narrow column of gas, smoke, and flame rises vertically into the air, like a dust devil.
With more intense heat, stronger updrafts, and enough dry fuel, a fire whirl grows into a fire tornado—a rotating funnel that extends from cloud to ground, moving at incredible speeds. Smoke plumes and pyrocumulus clouds can tower tens of thousands of feet in the sky.
Just like wind tornadoes, fire tornadoes leave destruction in their wake—trees uprooted, power poles snapped, and roofs blown off. They are visible on weather radar.
Fire tornadoes are rare but are being recorded more often in recent years. In 2018, a fire tornado was captured on video along the Colorado River near the Arizona-California state line. In 2020, at least three huge wildfires in California spawned them. One led the National Weather Service to issue an historic first—a fire tornado warning.
With climate change, continued drought and more extreme fires, it’s possible there will be more occurrences of fire tornadoes in the Southwest. Researchers are working in labs to replicate them, with the hope of being able to forecast them in the real world, potentially allowing time to warn of their impending destruction.