Daily Archives: July 1, 2025

According to the American Meteorology Society’s glossary, a landspout is a colloquial name for a small tornado whose vorticity (a vector that measures local rotation in a fluid flow) originates in the boundary layer and has a parent cloud in its growth stage. Landspouts occur when colliding winds at the surface begin to make a vortex and then a developing thunderstorm passes overhead. The updrafts from that thunderstorm draw the rotating vortex upward and give it a tornado-like appearance. While relatively weak compared to traditional tornadoes, landspouts can be strong enough to cause damage and warrant caution.

The term “landspout” was coined by atmospheric scientists in the 1980s to describe a type of vortex associated with thunderstorms that do not possess a strong mid-level mesocyclone. A mesocyclone is a cyclonically rotating vortex, around 2–10 km in diameter, in a convective storm. Strong tornadoes form in mesocyclones.
Continue reading →