Cyclone

[9] Extratropical cyclones begin as waves in large regions of enhanced mid-latitude temperature contrasts called baroclinic zones.

These zones contract and form weather fronts as the cyclonic circulation closes and intensifies.

A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the subtropical jet stream.

Weather fronts mark the boundary between two masses of air of different temperature, humidity, and densities, and are associated with the most prominent meteorological phenomena.

Tropical cyclones form due to latent heat driven by significant thunderstorm activity, and are warm core.

[13] Waterspouts can also form from mesocyclones, but more often develop from environments of high instability and low vertical wind shear.

[16] Henry Piddington published 40 papers dealing with tropical storms from Calcutta between 1836 and 1855 in The Journal of the Asiatic Society.

[9] Cyclogenesis is an umbrella term for several different processes that all result in the development of some sort of cyclone.

Extratropical cyclones begin as waves along weather fronts before occluding later in their life cycle as cold-core systems.

[13] Waterspouts can also form from mesocyclones, but more often develop from environments of high instability and low vertical wind shear.

Tropical cyclogenesis, the development of a warm-core cyclone, begins with significant convection in a favorable atmospheric environment.

An extratropical cyclone is a synoptic scale low-pressure weather system that does not have tropical characteristics,[33] as it is connected with fronts and horizontal gradients (rather than vertical) in temperature and dew point otherwise known as "baroclinic zones".

Polar lows were first identified on the meteorological satellite imagery that became available in the 1960s, which revealed many small-scale cloud vortices at high latitudes.

Antarctic systems tend to be weaker than their northern counterparts since the air-sea temperature differences around the continent are generally smaller [citation needed].

[38] The systems usually have a horizontal length scale of less than 1,000 kilometres (620 mi) and exist for no more than a couple of days.

Polar lows can be difficult to detect using conventional weather reports and are a hazard to high-latitude operations, such as shipping and gas and oil platforms.

Although subtropical storms rarely have hurricane-force winds, they may become tropical in nature as their cores warm.

[44] A tropical cyclone is a storm system characterized by a low-pressure center and numerous thunderstorms that produce strong winds and flooding rain.

They develop over large bodies of warm water,[48] and hence lose their strength if they move over land.

Storm surges can produce extensive coastal flooding up to 40 kilometres (25 mi) from the coastline.

[46] Although their effects on human populations can be devastating, tropical cyclones can also relieve drought conditions.

[50] They also carry heat and energy away from the tropics and transport it toward temperate latitudes,[46] which makes them an important part of the global atmospheric circulation mechanism.

A tropical cyclone can become extratropical as it moves toward higher latitudes if its energy source changes from heat released by condensation to differences in temperature between air masses.

[52] In the southern hemisphere, it tends to be located near the edge of the Ross ice shelf near 160 west longitude.

[55] When the polar vortex is strong, its effect can be felt at the surface as a westerly wind (toward the east).

A weak inverted surface trough within the trade wind is generally found underneath them, and they may also be associated with broad areas of high-level clouds.

Downward development results in an increase of cumulus clouds and the appearance of a surface vortex.

[59] Air rises and rotates around a vertical axis, usually in the same direction as low-pressure systems[60] in both northern and southern hemisphere.

[63] Dust devils are usually harmless, but can on rare occasions grow large enough to pose a threat to both people and property.

Cyclonic storms are common on giant planets, such as the Small Dark Spot on Neptune.