"Tornadoes develop when you have a very large difference in the wind between one level of the atmosphere and another. So just say you've got a northerly wind on the surface and a southerly wind above the surface," Mr Haigh said.

"Then let's say there's an instability above this layer, basically you've got rising air and the rising air, this air gets lifted into an updraft. This wind difference then becomes a wind direction difference between two points on a horizontal surface above the ground and as that rises up you get rotation.

"As that gets lifted that becomes a rotating air column. That will then shrink and stretch and because you've got rotation there, as the extent of the horizontal rotation shrinks the rotation speeds up. The rapidly rotating air then becomes a tornado.

"You need something pulling or sucking up this air draft and that requires rising air from above. You need a relative amount of humidity as well, and the cloud base tends to be quite low when tornadoes form.

"The kind of cloud were talking about is a kind of lumpy cloud - it's called a cumulus cloud. You need a lumpy cloud going to quite high in the atmosphere.

"The bottom part of the cloud may have been rotating and there may have been a protrusion initially. When a tornado forms you sometimes get a ropey cloud formation which connects the cloud all the way to the ground."

Due to the highly specific conditions required to produce a tornado, they "are usually very short-lived", Mr Haigh said.

"There's no doubt it was a tornado, based on the pictures and it's kind of a rare event but not a totally unheard of event."

"They do occur from time to time in Australia and they're normally on the lower end on the intensity scale."