[scheme271]

Coriolis effect is common in large (~10s of km) systems but I'm not sure the effect is strong enough to affect something as turbulent as air rising from a fire. At small sizes, like water in a toilet, it's not large enough to determine which direction the water swirls.

[labster]

I hear you but some of the big fire driven storms really do get up to the mid-range of mesoscale, where Coriolis force starts to play a role. It obviously won’t have the same role as synoptic phenomena, but I suspect most fire whirls have cyclonic motion, unless local orography really favors anticyclonic flow.