Geography homework help (not that hard, I'm only 13)..?

I've got this geography project and I have to conduct a weather study of an adverse weather type/occurrence such as, hurricanes, avalanches, famine, tornado's', you know, and I want to do mine on hurricanes, and I'm going to do about Hurricane Katrina. The first thing I have to do if wrte what a hurricane is, it might sound easy but I can't seem to find something right. It's either too simple or too like, GCSE hard! I'm only 13 so it needs to be fairly simple, but with like a few points and words in there to make it smarter. Idea's? It needs to be about half a page, or however.