From: Steve (Primus) (Avatar) 30/10/2001 5:40:08 Subject: STEVE'S WEATHER FAQ post id: 476397 Typhoons. How they work? Why they start? And what's the difference between typhoons, cyclones, and hurricanes? Typhoons, hurricanes and tropical cyclones are all tropical revolving storms. They are called Hurricanes in the Atlantic and the western Pacific, Typhoons in the South China Sea and Tropical Cyclones in the Indian and South Pacific oceans. There is some information on Tropical Cyclones on the Bureau of Meteorology web page here http://www.bom.gov.au/lam/cpage.shtml Learn About Meteorology The three requirements for a tropical revolving storm are (1) a sea surface temperature greater than 26C, (2) a pre-existing area of low pressure and (3) sufficient turning force from Coriolis. This means that they will only form in summer when the equatorial trough is over the area and not closer to the equator than 5 degrees. Mostly they form between 5 and 15 degrees north and south. The warm water provides the fuel for the storm from evaporation, the low pressure provides the instability so the clouds will develop to great heights and the Coriolis effect provides the rotation in the storm.