Hurricanes and Tropical Storms
Hurricanes are gigantic tropical storms that can be hundreds of kilometres wide. They bring along very strong winds and a lot of rainfall. They often cause flooding near the coasts and sea levels rise.
Hurricanes occur in many parts of the world. In the Pacific Ocean they are called typhoons and in Australia they are willy-willies. In the Atlantic Ocean and the Caribbean Sea they are called hurricanes.
How hurricanes start
Hurricanes are born over tropical oceans, usually during late summer and early autumn. They need two things to get them started: heat and moist air.
During the summer the ocean surface heats up and warm moist air starts to rise. Cool air sinks down to replace it. This creates an area of low pressure.
The rotation of the earth creates winds around the centre of such a low pressure area. In the northern hemisphere the air moves counterclockwise, in the southern part clockwise. Such a system is called a cyclone.
When warm air rises it cools and creates clouds. Soon, thunderstorms form and it starts to rain.
All hurricanes begin as cyclones but not all cyclones become storms or hurricanes. Some die out a few days after they start. They don’t have enough energy to become a hurricane. When winds are stronger than 119km an hour a storm officially becomes a hurricane.
Structure of a hurricane
The centre of a hurricane is called the eye, a calm area with little rainfall. It is about 30 to 50km wide. Inside the eye the sea can rise up to one metre because the air moves up.
The eyewall is around the eye. This is an area of thunderstorms, rain and the strongest winds—up to 300km an hour.
1. Find synonyms to the words:
To occur, to replace, inside, area, to need.
2. Answer the following question using your own words:
a. Where are hurricanes born?
b. What is the structure of a hurricans?
3. Give your opinion about the information supplied by the text. Composition 30-40 words.