Cyclones

Cyclones are large scale air mass that rotates around a strong center of low atmospheric pressure.

Based on the geographical location, the Cyclones are of two types namely Tropical Cyclones and Temperate Cyclones (Extra Tropical Cyclones).

TROPICAL CYCLONES

Tropical Cyclones are violent storms that originate over the seas in the Low pressure belt of the tropical areas and move eastward over to the coastal areas.
They bring about large scale destruction caused by violent winds, very heavy rainfall and storm surges which make them as one of the most devastating natural calamities.
They are known as Cyclones in the Indian Ocean, Hurricanes in the Atlantic, Typhoons in the Western Pacific and South China Sea, and Willy-willies in the Western Australia.
They originate only over the seas because of the need of continuous moisture to energize the Cyclones regularly. This is why they dissipate once reaching the land.
They are violent because of the energy coming from the condensation process in cumulonimbus clouds surrounding the Cyclones.
They move from east to west because they are facilitated by the Trade wind.

TEMPERATE CYCLONE

This system develops in the mid and high latitude (around 600 latitudes) along the polar front (boundary between the warm air and cold air).
As the polar front develops over entire polar frontal system, this cyclone affects a much larger area of around 2000 km. Also it develops over land and sea both as far as there is frontal system.
It moves from west to east due to the influence of Westerlies.
When the pressure drops along the front, the warm air moves northwards and the cold air move towards south setting in motion for anticlockwise cyclonic circulation.
The warm air glides over the cold air and a sequence of clouds appear over the sky ahead of the warm front and cause precipitation.
The cold front approaches the warm air from behind and pushes the warm air up. As a result, cumulus clouds develop along the cold front.
The cold front moves faster than the warm front ultimately overtaking the warm front. The warm air is completely lifted up and the front is occluded and the cyclone dissipates.