Gustnado

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A Gustnado is a slang term for a type of short-lived, shallow, cyclonic circulation that can form in a severe thunderstorm. While it derives its name from the tornado, it has very little in common with tornadoes structurally.

The most common setting for a gustnado is a severe thunderstorm (55+ mph winds). They are triggered by gust fronts (hence the name) in thunderstorms. The cool air in the gust front acts like a small scale cold front, it slices under the warm air ahead of it and creates upward motions. The friction from this interaction creates spinning columns of air, or eddys, which can create a gustnado (to get the general idea of this, picture an area of leaves swirling on a windy day, just on a much larger scale).

The average gustnado lasts no more than a few seconds to a few minutes each, although there can be several generations. Most have the winds of a F0 or F1 tornado, and are commonly mistaken for tornadoes. However, unlike tornadoes, the rotating column of air in a gustnado usually does not extend all the way to the base of the thundercloud. Gustnadoes actually have more in common with dust devils. They are not considered true tornadoes by most meteorologists and are not included in tornado statistics

Although the term "gustnado" has yet to fully enter the weather vernacular, it is becoming increasingly popular in the Midwest, where gustnados are the most common.