The fire devils work more like dust devils than tornadoes. They rise from preexisting hot spots in wildfires and the rising air forms a vortex.
One has to wonder how many religious sightings were in fact just weather phenomenons like fire devils. Consider The angel of the Lord appeared to him in a blazing fire from the midst of a bush; and he looked, and behold, the bush was burning with fire, yet the bush was not consumed” (Exodus 3:2)
Source: MSNBC
