A landspout is a tornado, but a tornado may not be a landspout. Wait, what?

Tornadoes and landspouts are nothing new to the residents of Arkansas or Oklahoma, but how they form is very different from each other. Landspouts are still tornadoes, but with an extra twist (get it, an extra twist for a twister! 😁). Let’s start with the more common supercell tornadoes.

Supercell Tornadoes

A tornado is “a rapidly rotating column of air extending vertically from the surface to the base of a cumuliform cloud, often with near-surface circulating debris/dust when over land or spray when over water” (American Meteorological Society).

The classic tornado most of us think about is called a supercell tornado. They form in a thunderstorm that develops a mesocyclone, meaning the updraft (current of rising air in a thunderstorm) is actually rotating.

Supercell tornadoes occur the most often and are typically the most dangerous. Their size can range from very narrow & rope-like to monstrous wedges.

There are many theories to how supercell tornadoes form, including the “horizontal tube theory” outlined in a previous Weather 101.

Landspout

A landspout forms in a non-supercell thunderstorm (or ordinary thunderstorm) and does not have a rotating updraft. They occur near boundaries of colliding air masses and are often short-lived and relatively weak.

Unlike tornadoes from a supercell, it is very difficult to detect landspouts without eye-witness reports.

This is because the radar scans upwards on an angle due to the curvature of the Earth, but meteorologists can determine where the environment is most favorable for landspout development.

Regardless, all tornadoes are dangerous and you should take shelter immediately if one forms near you.

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