Fire tornado in Australia
A case study of a fire tornado that measured half a kilometre across at the base. Canberra, 2003.
Another one, slightly different structure, in Alaska:
Extreme Fire Behavior on the Tetlin Junction Ridge Fire (#414) on 8/16/13
I assume the different structure is because of different fuel type (pine) and the weather. The more dangerous the weather, the more likely tornados are. Pine ignition point is higher than eucalyptus?
A mini one: