A year 7 student once asked me how a hurricane forms, so I have included an animated presentation below. (You will need to have flash player installed to view it!). Basically, when thunder storm clusters drift over areas of the sea in an area where strong winds (known as trade winds) blow in opposite directions, warm air rises, and the storm starts to spin. Because there is lots of warm air at the surface in these areas, it rises rapidly, sucking cooler air downwards and creating a vortex of spinning air, which gets faster and faster, causing high wind speeds and rain. When a hurricane reaches land, it can have devastating effects...
