Storms are known by different names throughout the world-hurricanes in the West Indies, willy-willy in Australia, twisters in the US, typhoons in China and Far East, and cyclones in the Indian Ocean. The collective name for these disturbances in air circulation patterns is ‘tropical cyclones’ as these tend to occur in the tropics (Tropic of Cancer and Tropic of Capricorn). Though the names of the storms occurring in different parts of the world differ, the manners in which these develop or form are identical.
Just as an engine or motor burns fuel for functioning, a developing or evolving storm makes use of moist warm air to gain strength. This precondition for storm or cyclonic development can only be fulfilled in areas where warm and humid air is profusely available-seas and oceans. Once the surface water over oceans gets heated it evaporates eventually, and being lighter than the surrounding air, it rises to upper stratums of the atmosphere. Continual heating and evaporation of the surface water that ascends upwards forming cumulonimbus clouds result in the creation of a low-pressure trough.
As is the tendency of atmospheric air, it tends to move from areas of high pressure zones to areas of low pressure troughs. The continuously churning ‘spirals’ and ‘whirlpools’ of air condense or cool down to form rain-bearing clouds. The clouds which are essentially highly crystallized and vaporized water droplets now being heavier (than the surrounding air) coalesce to form storms that begins to circulate and move towards the land as wind speeds reach up to 39mph. At this speed, the storm is termed as ‘tropical’ and when the wind speed exceeds 70mph, the storm becomes a hurricane. These storms vent their fury once they reach deep into the mainland causing large-scale loss of life and property. Eventually, they die out as the fuel of moisture laden warm air is no longer available on land.