The Australian Cyclone Severity Scale was introduced around 1992. The wind gusts refer to peak 3-second wind gusts expected in the zone of maximum winds. These winds are then related to a description of the typical effects of these winds [indicative only]. The typical effects refer to the zone of maximum winds and give a general idea of the expected worst conditions [http;//www.bom.gov.au/info/cyclone]. These typical effects were established through consultation between the Australian Bureau of Meteorology and Greg Reardon at the Cyclone Testing Station, James Cook University. Note that no mention is made of likely storm surge effects [or other flooding] or central pressures for the various categories [P. Alford, pers.comm.].

The Australian scale categories is based on a conversion from sustained wind speeds in various wind categories to expected 3-second peak wind gusts from those sustained wind regimes. Categories 1 and 2 relate to the sorts of wind gusts expected from gales and storm force winds [in the Beaufort scale] respectively [using a conversion factor of 1.41 and rounding off, it seems, to the nearest 5 km/h]. Categories 3 to 5 refer to wind gusts expected in the Beaufort hurricane force winds range. The connection with gale-, storm- and hurricane-force winds ensures consistency with ocean wind warnings. The motivation for the use of wind gusts rather than mean 10-minute winds is that it is the windgusts which cause the damage. The choice of gust ranges for categories 3, 4, and 5 is based on significant "jumps" between ranges in the expected damage, based on James Cook University work][P Alford, pers. comm.].

The Australian Cyclone Severity Scale is not related to the Saffir-Simpson scale. The version of the ACSS presented on p9-20 of the Global Guide to Tropical Cyclone Forecasting [ed. Greg Holland, WMO-TD 560, 1993], shows maximum sustained wind ranges as 10-minute averages. This seems to relate only approximately to the actual scale which uses wind gusts [P Alford, pers. comm. 15/5/98].