Tropical storms include typhoons, hurricanes and cyclones. The definition of each is the same but the type depends on the geographical area it is found in. Hurricanes form in the Atlantic, or the northeast pacific, typhoons in the Northwestern Pacific, and cyclones in the mid and southern Pacific and Indian Ocean.
Initially a tropical depression forms, this is an area of low pressure around which winds are moving. Once the winds reach over thirty-nine miles per hour the depression is redefined as a cyclone and is named. Names are used to able easy identification of individual storm systems by the public and meteorological observers. In the tropical storm season there may be several storm systems spread around the world, or in specific area.
The first incidence of the naming of storms seems to have been by an Australian meteorologist, early in the twentieth century, who named the storms randomly after politicians he disliked. Later, during world war two, the American navy introduced an informal system of naming storms in the Pacific after women, usually wives and girlfriends.
In the 1950's this system was also adopted in the Atlantic, replacing the use of the phonetic alphabet. By the 1970's both male and female names were being used. The system has now developed to prepared lists of names. Each major area of the world maintains its own list.
The Australian system uses alternating male and female names in alphabetical order, as does the American system. The pacific area however has a list of names that refer to plants, animals, birds and storm characteristics. These names are not arranged alphabetically, but rather alphabetically by the country that provided the name, for instance a Chinese name, then a Japanese name etc.
Each tropical warning center has the right to name tropical storms that form in their area, and this name remains constant even if the storm passes into another area.
The list begins again each year at A. The lists of names that use people's names have twenty-one letters, the letters Q, U, X, Y and Z not being used due to a shortage of names beginning with that letter.
The names are reused on a rotating list but if a particular storm causes massive damage and loss of life that name is retired from the list. This is as a mark of respect and to avoid confusion in later years. For this reason the names Katrina and Andrew will not be used again in the Atlantic, and Tracey will not be used in Australia.