- hurricanes in the USA and Caribbean
- cyclones in India, Bangladesh and other parts of southern Asia
- typhoons in Asia Pacific (esp. Japan)
- willy-willies in Australia
...are large storms (300-400 miles across, and 5-6 miles high) rotating round areas of extreme low pressure.
They occur between 5o and 20o N and S of the equator (Coriolis force nearer to the equator is too weak to cause the storm to rotate) where sea surface temperatures are 27oC or greater.
There's a nice summary from the Met Office here, an animated guide from the BBC, and you might like to have a look at Towers in the Tempest which looks at how "hot towers" cause hurricanes to intensify.
Plenty of info also from the National Weather Service and the National Hurricane Center.
As well as understanding how TRSs form, you need to know about the effects they have, and how these are likely to be different in countries/regions at different levels of development.
Hurricane Katrina...
hit the south-eastern USA in August 2005. It is believed to have killed about 1500 people, and with the cost of damage estimated to have been about $300 billion, was the most costly disaster to hit the USA.
The Met Office have put together a very good case study page (click on the satellite image of Katrina above) which looks at the physical impacts, human impacts and responses, and also has a set of activities for you to have a go at.
There are lots and lots of other sources of information available - one of the best is probably the BBC's In Depth Guide and it's well worth spending some time investigating this properly.
This "Storm Viewer" shows the track of Hurricane Katrina, but also shows you how the pressure, wind speeds and precipitation changed with the development of the hurricane. Various similar animations of other hurricanes here.
Cyclone Sidr next...
