Very scary: Fire whirls, fire devil or fire tornado, is a rare natural phenomenon. It occurs when a fire, combined by certain air temperature and currents, forms a whirl that rises into the air like a tornado. They can be actual whirlwinds that disengage from the flames, or else can become a vortex of flame. The fire whirl usually occurs during bush fires.
Fire Whirl: Fire whirls occur when the heat from a fire drive the air above it in such a way as to form a vortex with the cooler air outside. If this vortex acquires a vertical spin then a fire whirl, a vortex sucking flames upwards, will form.