Tropical Cyclones are called “hurricanes” in America and “typhoons” in China.

A tropical cyclone is a powerful storm of tropical origin with:

Very low pressure (as low as 880 hPa [pressure units]),

Extremely high winds (may exceed 200kph)

And heavy rainfall.

A tropical cyclone has a diameter of 100-500km.

It has an eye, about 30km across, at its centre, with much lighter winds.

In the Southern Hemisphere, tropical cyclones rotate around the eye in a clockwise direction.

The strongest winds and heaviest rainfall are just outside the eye.

Class BEAUFORT SCALE

Description Average Wind Speed

1 8-9 Gale Force 70kph

2 10-11 Storm Force 100kph

3 12 Hurricane Force 140kph

4 12+ Major Hurricane 170+kph