Cyclones developed in the regions lying between the tropics of Capricorn and Cancer
are called Tropical Cyclones which are not regular and uniform like extra tropical or temperate
cyclones. There are numerous forms of these cyclones, which vary considerably in shape,
size, velocity and weather conditions. The weather conditions of low latitudes mainly rainfall
regimes are largely controlled by Tropical Cyclones.
(a) Size of tropical cyclones varies considerably. On an average their diameters range
between 80 km and 300 km.
(b) Weak cyclones move at the speed of about 32 km per hour while hurricanes attain
the velocity of 180 km per hour or more.
(c) Tropical cyclones become more vigorous over the oceans but become weak and
feeble while moving over land areas. This is why these cyclones affect only the
coastal areas e.g. Tamil Nadu, Orissa and West Bengal coasts of India.
(d) The centre of the cyclone is characterized by extremely low pressure.
(e) Tropical cyclones are not characterized by temperature variations in their different
parts because they do not have different fronts.
(f) There are no different rainfall cells hence each part of the cyclones yields rainfall.
(g) Tropical cyclones are not always mobile. Normally, they move from east to west
under the influence of trade winds
(h) Tropical cyclones are confined to a particular period of the year (summer season).