A gustnado is a short-lived, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm.

The name is a portmanteau by the elision of "gust front tornado", as gustnadoes form due to non-tornadic straight-line wind features in the downdraft (outflow), specifically within the gust front of strong thunderstorms.

Gustnadoes tend to be noticed when the vortices loft sufficient debris or form condensation cloud to be visible although it is the wind that makes the gustnado, similarly to tornadoes. As these eddies very rarely connect from the surface to the cloud base, they are very rarely considered as tornadoes. The gustnado has little in common with tornadoes structurally or dynamically in regard to vertical development, intensity, longevity, or formative process - as classic tornadoes are associated with mesocyclones within the inflow (updraft) of the storm, not the outflow.

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