It's a rare weather event, but a fire tornado was recently caught on camera in a drought-stricken region of Brazil. The tornado started fires in nearby fields, which were contained overnight.
The vortex of fire resulted from months of drought in the region, combined with brush fires and strong, dry winds.
Though a rare phenomenon, the formation of a fire tornado, or fire whirl, is quite simple.
When there is a warm updraft of air and convergence of fire, say from a wildfire, a vortex of flame can occur. As the heated air from the fire rises, strong air currents cause flame to spin, shaping it into a tornado.
At the link, you can read about how to make your own fire tornado at home.
Link via Sci Fi Wire