Tropical cyclone scales

Background

Tropical cyclones are defined as being warm cored, non-frontal synoptic cyclones, that develop over tropical or subtropical waters, with organized atmospheric convection and have a definite cyclonic surface wind circulation. They are classified by the wind speeds located around the circulation centre and are ranked, by the World Meteorological Organization's Regional Specialized Meteorological Centers on one of five tropical cyclone scales. The scale used for a particular tropical cyclone depends on what basin the system is located in; with for example the Saffir–Simpson hurricane wind scale and the Australian tropical cyclone intensity scales both used in the Western Hemisphere. All of the scales rank tropical cyclones using their maximum sustained winds, which are either observed, measured or estimated using various techniques, over a period between one and ten minutes.