Landspout

About

In 1985, atmospheric scientist Howard B. Bluestein coined the word "landspout" to describe a specific type of tornado unrelated to a mesocyclone.

A landspout is a colloquial term for tornadoes that occur with a parent cloud in its growth stage and with its vorticity starting in the boundary layer, according to the Glossary of Meteorology.

There isn't a mid-level mesocyclone already present in the parent cloud. Because it resembles "a feeble Florida Keys waterspout over land," the landspout was given that name.

Landspouts often aren't as strong as tornadoes connected with mesocyclones, which are where the strongest tornadoes develop.

Features

When an updraft pushes boundary layer vorticity upward into a vertical axis and tightens it into a powerful vortex, a landspout, a type of tornado, emerges during the growth stage of a cumulus congestus or infrequently a cumulonimbus cloud.

These often lack a mesocyclone or any pre-existing spin in the cloud and are smaller and weaker than supercell tornadoes. Landspouts are infrequently picked up by Doppler weather radar due to their lower depth, smaller size, and weaker intensity (NWS).

Landspouts typically take the shape of a translucent and extremely laminar helical tube, and their formation is quite similar to that of waterspouts.

Since a fast rotating column of air makes contact with the ground and a cumuliform cloud, landspouts are categorised as tornadoes.

Many landspouts are first observed as debris spinning at the surface before eventually filling in with moisture and dust since not all landspouts are visible.

Landspout (and even mesocyclone tornado) development can be impacted by orography.


Source: Indian Express






Posted by on 1st Jul 2022