Mesocyclone in the context of "Cyclogenesis"

A dust devil (also known regionally as a dirt devil) is a strong, well-formed, and relatively short-lived whirlwind. Its size ranges from small (18 in/half a metre wide and a few yards/metres tall) to large (more than 30 ft/10 m wide and more than half a mile/1 km tall). The primary vertical motion is upward. Dust devils are usually harmless, but can on rare occasions grow large enough to endanger both people and property.

They are comparable to tornadoes in that both are a weather phenomenon involving a vertically oriented rotating column of wind. Most tornadoes are associated with a larger parent circulation, the mesocyclone on the back of a supercell thunderstorm. Dust devils form as a swirling updraft under sunny conditions during fair weather, rarely coming close to the intensity of a tornado.

A landspout is a type of tornado not associated with a mesocyclone. The term was coined by atmospheric scientist Howard B. Bluestein in 1985. The Glossary of Meteorology defines a landspout as:

Landspouts are typically weaker than mesocyclone-associated tornadoes spawned within supercell thunderstorms, in which the strongest tornadoes form.

A supercell is a thunderstorm characterized by the presence of a mesocyclone, a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four main classifications of thunderstorms—supercell, squall line, multi-cell, and single-cell—supercells are the least common overall and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. They tend to last 2–4 hours, but under highly favorable conditions, can last even longer.

Supercells are often put into three classification types: "classic" (normal precipitation level), low-precipitation (LP), and high-precipitation (HP). Low-precipitation supercells are usually found in climates that are more arid, such as the high plains of the United States, and high-precipitation supercells are most often found in moist climates. Supercells can occur anywhere in the world under the right pre-existing weather conditions, but they are most common in the Great Plains of the United States in an area known as Tornado Alley. A high number of supercells are seen in many parts of Europe as well as in the Tornado Corridor of Argentina, Uruguay, southern Brazil, and Paraguay.

A gustnado is a brief, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm. The name is a portmanteau by elision of "gust front tornado", as gustnadoes form due to non-tornadic straight-line wind features in the downdraft (outflow), specifically within the gust front of strong thunderstorms. Gustnadoes tend to be noticed when the vortices loft sufficient debris or form condensation clouds to be visible, although it is the wind that makes the gustnado, similar to tornadoes. As these eddies very rarely connect from the surface to the cloud base, they are very rarely considered as tornadoes. The gustnado has little in common with tornadoes structurally or dynamically in regard to vertical development, intensity, longevity, or formative process—as classic tornadoes are associated with mesocyclones within the inflow (updraft) of the storm, not the outflow.

The average gustnado lasts a few seconds to a few minutes, although there can be several generations and simultaneous swarms. Most have the winds equivalent to an F0 or F1 tornado (up to 180 km/h or 110 mph), and are commonly mistaken for tornadoes. However, unlike tornadoes, the rotating column of air in a gustnado usually does not extend all the way to the base of the thundercloud. Gustnadoes actually have more in common with (minor) whirlwinds. They are not considered true tornadoes (unless they connect the surface to the ambient cloud base in which case they'd become a landspout) by most meteorologists and are not included in tornado statistics in most areas. Sometimes referred to as spin-up tornadoes, that term more correctly describes the rare tornadic gustnado that connects the surface to the ambient clouded base, or more commonly to the relatively brief but true tornadoes that are associated with a mesovortex.

A fire whirl, fire devil or fire tornado is a whirlwind induced by a fire and often (at least partially) composed of flame or ash. These start with a whirl of wind, often made visible by smoke, and may occur when intense rising heat and turbulent wind conditions combine to form whirling eddies of air. These eddies can contract to a tornado-like vortex that sucks in debris and combustible gases.

The phenomenon is sometimes labeled a fire tornado, firenado, fire swirl, or fire twister, but these terms usually refer to a separate phenomenon where a fire has such intensity that it generates an actual tornado. Fire whirls are not usually classifiable as tornadoes as the vortex in most cases does not extend from the surface to cloud base. Also, even in such cases, those fire whirls very rarely are classic tornadoes, as their vorticity derives from surface winds and heat-induced lifting, rather than from a tornadic mesocyclone aloft.