A wildfire in Southern California spawned a fire whirl, also known as a firenado or fire tornado.

A fire whirl is a “spinning vortex column of ascending hot air and gases rising from a fire and carrying aloft smoke, debris and flame,” according to the Bureau of Land Management’s Glossary of Wildland Fire Terminology.

Fire whirls range in size from less than 1 foot to more than 500 feet in diameter,” the glossary said. “Large fire whirls have the intensity of a small tornado.”

These fire whirls can form in any size fire, but they are most destructive in large ones. Created by cool air rushing to take the place of hot air, the whirl’s spinning can hurl embers and sparks great distances. Whirls usually intensify a wildfire.

Fire whirls are more likely to occur where winds are forced to change directions, such as near a grove of trees.

Thursday’s firenado occurred during the Sherpa Fire, which has burned about 1,400 acres west of Santa Barbara, Calif. Authorities evacuated 400 homes and businesses, Reuters reported.