gustnado

A gustnado is a small, short-lived, rotating column of air that forms along a gust front or downburst rather than from a thunderstorm’s central rotating updraft. It typically appears as a narrow, dust- or debris-filled column that may briefly touch the ground but is not connected to a cloud base by a visible funnel. The rotation arises from near-ground wind shear within the gust front, which is stretched upward as the gust front advances.

Gustnadoes are often mistaken for tornadoes because they can cause localized damage and resemble a twister at ground level. However, they differ from tornadoes in origin and structure: tornadoes generally form from mesocyclones within a thunderstorm and have a stronger, more persistent rotation that is connected to the cloud base with a visible funnel, whereas gustnadoes are generated along the gust front and may have little to no cloud contact.

Duration and impact vary, but gustnadoes are usually brief—ranging from a few seconds to several minutes—and typically produce minor to moderate damage consistent with weak to strong straight-line winds and debris. They frequently occur along squall lines or in the wake of downdrafts, and can be observed in many high-wwind environments, including mid-latitude plains and other storm-prone regions.

Detection and warnings rely on surface observations, visual confirmation of rotation along a gust front, and, when available, radar indications of strong wind shear in the boundary layer. Public safety guidance emphasizes treating any observed rotating wind feature along a gust front as hazardous and seeking shelter as appropriate, even if a tornado warning is not in effect.