Landspouts

Landspouts are tornado-like vortices that form on land, typically without a deep, rotating thunderstorm (mesocyclone) in the parent storm. They usually occur along convective boundaries such as gust fronts, outflow boundaries, or drylines when warm, moist air rises and encounters wind shear near the surface.

Formation involves preexisting horizontal vorticity in the low-level air caused by wind shear along the boundary. An updraft of a developing thunderstorm tilts this vorticity into the vertical, creating a rotating column that reaches the surface. The parent storm is often a non-supercell thunderstorm, and the funnel is usually short-lived and less intense than a classic tornado.

Landspouts are typically weak to moderate, most often rated EF0–EF1, with durations of only a few minutes. They can cause localized damage to trees, roofs, and vehicles, and may produce debris-laden dust as the funnel contacts the ground.

Distinctions from other phenomena: they are distinct from waterspouts, which form over water; from gustnado, which forms along gust fronts with weaker structure; and from strong tornadoes spawned by mesocyclones. Landspouts form rapidly along boundary features and often lack a strong radar signature of a mesocyclone.

Forecasts rely on observing boundaries, low-level wind shear, and storm development; spotting reports from trained observers help issue warnings. Safety-wise, treat a visible funnel or debris swirl as a tornado and seek shelter immediately.

Notable occurrences have been documented worldwide, with the United States reporting many along the Plains in spring, though landspouts are also reported in other regions.