Cyclone Nargis -- Urdu for "daffodil"

BANGKOK (Reuters) - Cyclone Nargis, the tropical cyclone that tore into Myanmar's Irrawaddy delta killing at least 22,000 people and leaving a million people homeless, takes its name from the word for "daffodil" in Urdu.

According to the U.S. National Hurricane Center website, the convention of naming of cyclones dates back to the early 20th century when an Australian weather forecaster named major storms after politicians he particularly disliked.

In a subtle example of meteorological allegory, the forecaster wanted to be able suggest a prominent public figure was "causing great distress" or "wandering aimlessly about the Pacific".

The U.S. Weather Bureau formally started giving North Atlantic cyclones women's names in 1953, before adapting to include men's names in 1979.

The idea was that naming a storm contributed to public awareness, and so helped people take evasive action.

Forecasters only started naming tropical cyclones in the North Indian Ocean, where Cyclone Nargis was born, in 2004.

Names are contributed in alphabetical order by the nine countries whose coastlines border the ocean -- Bangladesh, India, the Maldives, Myanmar, Oman, Pakistan, Sri Lanka and Thailand, and each name is used only once.

The main North Indian Ocean tropical cyclone season runs from May to November, and Nargis was the first one of the 2008 season to warrant a name.

Its predecessor at the end of the 2007 season was Cyclone Sidr, which hit Bangladesh in November, killing 3,300 people.

Nargis was also the name of one of India's most famous actresses. Nargis, whose hit films of the late 1940s and 1950s remain popular today, was married to actor-turned-politician Sunil Dutt and mother of current Bollywood bad boy Sanjay Dutt.

(Writing by Ed Cropley; Editing by Alex Richardson)