Fire-Tornado Pictures: Why They Form, How to Fight Them

Fueling the Flames

Photograph by Simon Gray, My Shot

A fire tornado rises from burning peat on a farm in Bangor, U.K., in 2008.

Combustible, carbon-rich gases released by burning vegetation on the ground are fuel for most fire tornadoes, Forthofer said. "The vegetation on the ground heats up enough to release gas, but some of the gas can't combust, because it doesn't have enough oxygen around it."

(See "Vast Peat Fire May Burn for Months in North Carolina"[June 2008].)