GCSE Geography | What are the Features of a Tropical Storm? (Weather Hazards 5)
- AQA, Edexcel, OCR, Eduqas
Last updated 19 Jul 2023
The diagram at the bottom of this page shows a cross-section of the structure of a tropical storm, and the photo below is a satellite image that shows the swirling wind and cloud around the calm eye of the storm.
As you move across a tropical storm you will find these conditions...
The temperature and air pressure drops at the beginning of a tropical storm - this causes air to rise and clouds to form and winds start to pick up.
The tropical storm continues which results in the air pressure falling more rapidly, the wind increasing, cumulonimbus cloud forming, leading to heavy rainfall.
In the centre of the storm conditions are calm with no wind or rain - this is called the eye of the storm. The sun is able to get through so it gets warmer. However air pressure is very low.
On the other side of the eye the wind and rain dramatically increases again - temperature drops and the air pressure starts to rise.
At the end of the tropical storm there is a rise in pressure and temperature, and winds and rain decrease.
The reasons that tropical storms spin is due to the Coriolis effect, which bends and spins the warm rising air. You can see this spinning really clearly on satellite images. In the northern hemisphere hurricanes bend to the right which makes the clouds swirl anticlockwise, whereas in the southern hemisphere cyclones bend to the left and swirl clockwise.
What is the Coriolis effect?
Winds blow from high pressure zones to low pressure zones, but they blow in a curve rather than a straight line due to the Coriolis effect. This happens because of the curvature of the Earth - the Earth has to spin much faster at the Equator than at the poles because it is so much wider. This difference in spin speed causes the wind to bend as it blows across the Earth.