Cyclone of tropical origin of small diameter (some hundreds of kilometres) with minimum surface pressure in some cases less than 900 hPa, very violent winds and torrential rain; sometimes accompanied by thunderstorms. It usually contains a central region, known as the “eye” of the storm, with a diameter of the order of some tens of kilometres, and with light winds and more or less lightly clouded sky.<br /></p><p><br /></p><p>See WMO Code table 3704 "Shape and definition of the eye of the tropical cyclone" and WMO Code table 3790 "Intensity of the tropical cyclone" for candidate attributes for this class.<br /></p>