
“Remember, people are irreplaceable,” said Queensland Premier Anna Bligh as she urged residents between Cairns and Cardwell to evacuate immediately. “Do not bother to pack bags, just grab each other and get to an area of safety. This is the most serious and destructive cyclone you can have and it’s continuing to make its way towards the Queensland coast.”
As people all over Australia get set to watch the devastation caused by Cyclone Yasi and residents of Far North Queensland literally escape to protect their lives, we take a look at what a cyclone really is and what to do if you are ever affected.
What is a cyclone?
Tropical Cyclones are low pressure systems which develop in the tropics.
How are they formed?
In order for a cyclone to form, the ocean waters need to be at least 26°C. Water evaporates and forms clouds above the warm water. If there is low air pressure where the clouds are formed, it pulls them in and they begin to rotate. Clouds continue to form and begin to spin more. This is the stage when it can develop into a mature cyclone, or lose its momentum.
In order for the system to be categorised as a cyclone, its average sustained wind speed needs to exceed 63 kilometres per hour. To be classified as severe, the average sustained wind speed needs to exceed 118 kilometres per hour.