Lately there have been posts of the fire tornados popping up all over the internet. I must say, they are incredible to look at.
In case you're wondering how they form, here is a quick quote from Wikipedia:
"A fire whirl, colloquially fire devil or fire tornado, is a phenomenon—rarely captured on camera—in which a fire, under certain conditions (depending on air temperature and currents), acquires a vertical vorticity and forms a whirl, or a tornado-like vertically oriented rotating column of air. Fire whirls may be whirlwinds separated from the flames, either within the burn area or outside it, or a vortex of flame, itself."

via - nationalgeographic.com
Reminds me of the forced one you posted a while ago
http://fstoppers.com/very-cool-special-effect-fire-tornado