A viewer snapped a picture of a gustnado in Pinal County in 2013.
A gustnado may look like a tornado, but it forms differently.
A tornado forms in the updraft of a supercell thunderstorm and is attached to the base of the cloud.
Plus the vortex that creates a tornado drops down from the cloud.
This vortex is first called a funnel cloud and then a tornado when it makes contact with the ground.
A gustnado is formed from the gusty outflow of a powerful thunderstorm.
The outflow can kick up air ahead of the storm and some of that air can then start rotating to form a small vortex.
Notice that the gustnado in the picture below is not attached to the base of the cloud but out ahead of the storm.
A gustnado is independent of the storm cloud and forms from the surface of the Earth, stretching upward, which is similar to dust devil formation.