I took a question from a viewer last week asking me to explain what a “gustnado” is versus a tornado. While a gustnado is not a technical term, you may have heard it thrown around this severe weather season as they have developed a few times. For example, below was a viewer video sent in during the severe storms on Sunday June 30th. You can see what might be a gustnado near Luxemburg, IA.
Just north of Luxemburg at 5:00
Posted by Destiney Larson on Sunday, June 30, 2019
Similar to a dust devil, a gustnado really isn’t a tornado at all since it isn’t connected to the cloud base or any rotating wall cloud. They are little whirlwinds that develop off of a thunderstorm outflow or gust front. The dense, rain cooled air that moves out of the storm along the surface can form little eddies that will turn into a gustnado – visualized often by dirt or dust being kicked up.
Like a dust devil, these are pretty weak compared to a tornado but can from time to time cause damage if they are strong enough. Because they are associated with thunderstorms, any damage caused would be recorded as thunderstorm wind damage – not as tornadic damage.
A tornado is a violently rotating column of air that originates from the cloud base or parent storm. Sometimes you can see the funnel extending to the ground and sometimes you cannot. Gustnadoes, dust devils, and fire whirls are not considered tornadoes even though they are a vortex and may appear to be a tornado.
It is important to note that storms that develop a gustnado can also develop a tornado. If a warning is issued, be sure to seek shelter.