"Severe Tropical Cyclone Yasi - Looking Into The Eye Of A Monster"," They are not associated with a front but are formed over warm tropical waters and have gale force winds.
Once these winds hit 118 kilometers per hour the cyclone is classified as a severe tropical cyclone.
It is surrounded by a wall of dense cloud about 16 km high.
At 0600 hours on Wednesday February 2 2011 the word went out across the airways that Severe Tropical Cyclone Yasi had been upgraded to a Category 5 cyclone.
The chances of this storm causing widespread destruction were excellent.
At this time the authorities warned the public to expect a storm of catastrophic proportions.
Everyone had been watching Cyclone Yasi approach the North Queensland coast for days since the system formed over near Fiji.
The public were told to expect:
* Winds up to three hundred kilometers per hour.
* Deafening noise.
* Road closures.
* Loss of power to two hundred thousand people.
Storm surges are dangerous tsunami-like, fast-moving waters which are certain to inundate low-lying areas.
Unfortunately this storm surge was due to coincide with the high tide as Yasi crossed the coast.
Thirty thousand people had been urged and some ordered to evacuate to eleven nominated evacuation centers in the area in the path of the storm.
This was the largest hospital evacuation ever to take place in Australia.
The warnings or advice given to those residents who insisted on staying at their residence throughout the storm were to prepare for the cyclone with the following advice:
* Gather in the smallest room in the house.
* Gather mattresses and use for shelter in case the roof is blown off.
* Store water and fill the bath full of water for drinking water.
* Tape all windows to strengthen and reduce the risk of breakage.
* Ensure enough cash for food and petrol.
* Wear covered shoes to protect the feet from any instance of broken glass and other sharp objects.
* Ensure there is something to urinate into such as a portable potty.
* Clean the surrounding yard to ensure there are no potential missiles.
People will be then more likely to make good decisions if the need arises.
* As the eye of the cyclone passes over, be careful not to think that the cyclone has passed.
* Expect the wind to come from a different direction once the eye passes.
There was extensive damage to hundreds of buildings with roofs torn off and power poles knocked over.
The Prime Minister of Australia Ms Julia Gillard described the cyclone as the worst cyclone to hit Australia.
A man died from asphyxiation from the exhaust fumes from a generator he was running inside a closed room.
They obviously listened to the warnings and cooperated with authorities.
It proceeded inland North Queensland where it weakened to a tropical depression.
Roads, schools and airports were closed.
180,000 people were left without electricity.
The military together with emergency service volunteers were deployed to the area to assist with the cleanup.
One can only guess at the damage bill and the number of lives disrupted by this powerful freak of nature.