What Are Hurricanes

 

Hurricanes are very powerful, spiraling storms that produces winds of up to 300km/h (185mph). A combination of wind and torrential rain causes widespread flooding of the land and damage to buildings. Meteorologists call hurricanes and tropical cyclone, due to the nature of their movement and the areas in which they form. They are also known variously as typhoons and willy-willies.

                Hurricanes form when moist air is stirred up by heat over warm oceans. It is thought that areas on very low-pressure suck air into the centre of the low, producing strong surface winds. The air speeds up and spirals upwards, with water vapour condensing to form cumulonimbus clouds. Heat is generated, which makes air rise faster and causes the wind speed to increase even more.

                Hurricanes occur only in tropical areas (between 5 degrees and 20 degrees north and south of the Equator). Extreme temperature and humidity provide the right conditions for a hurricane to develop. They occur when the sea temperature rises above 27C (80F). The south-east coast of the USA and south-east Asia see many hurricanes.

                In the centre of a hurricane there is a column of air 30-50km (20-30 miles) wide. This is known as the “eye” of the hurricane. In the eye, the air is sinking slowly, and the wind is relatively light. As the eye passes over an area, the sky will clear, the rain will stop, and there will be a moment of calm. In the area immediately surrounding the eye- the eye wall- winds can reach up to 240km/h(150mph). Winds increase as the eye becomes narrower.