A gustnado is a brief, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm.
[3][4] The average gustnado lasts a few seconds to a few minutes, although there can be several generations and simultaneous swarms.
However, unlike tornadoes, the rotating column of air in a gustnado usually does not extend all the way to the base of the thundercloud.
[citation needed] While injuries or deaths are rare from gustnadoes, strong ones can cause damage and they are hazardous to drivers.
There is some speculation that a gustnado might have been responsible for the collapse of a stage at the Indiana State Fair on August 13, 2011 which killed 7 people and injured 58.