Today might be described as meteorology's birthday. It is 50 years old. The science, of course, has been around much longer, since Aristotle coined the phrase and offered bizarre explanations for the wind and rain in a book called Meteorologica.
Some 2000 years later, contemporary practitioners decided they might do better if they worked together, and so in 1873, the International Meteorological Organisation was established.
But perhaps the most important milestone in the development of weather forecasting occurred 50 years ago today when the World Meteorological Organisation, or WMO, came into being. It provides the framework on which the science as we know it now is based.
Established on March 23rd, 1950, WMO is the international body that co-ordinates meteorological effort on a global basis. It is a "Specialised Agency" of the United Nations - independent of, but formally approved by its parent body - and a sister organisation of the World Health Organisation, the International Civil Aviation Organisation, and many others.
Its membership includes virtually every independent nation in the world, 185 at the latest count.
Through a comprehensive set of agreed guidelines, WMO ensures that weather observations are carried out in a uniform way throughout the world; it organises the complex communications network necessary for the international exchange of these data; and it encourages in many other ways the co-operation between nations which makes modern weather forecasting and other meteorological activities possible.
The headquarters of WMO is in Geneva, where the secretary general and his staff cope with the daily administration of the organisation. But the major decisions are taken by the member-states, each of whom is represented on the technical commissions assigned to the various branches of meteorology.
WMO's challenge is awesome. It co-ordinates the collection, processing, and dissemination of meteorological information from an impressive constellation of polar-orbiting and geo-stationary meteorological satellites; from 10,000 land-based surface weather stations and 1,000 stations dedicated to obtaining data on the upper atmosphere; from 7,300 ships at sea, 300 moored buoys, 600 drifting buoys, and 3,000 participating aircraft.
In total, the system processes some 70,000 weather observations every day.
Meteorologists worldwide have for several decades celebrated March 23rd each year, the anniversary of WMO's establishment, as World Meteorological Day. A theme is chosen each year, such as "Weather, Climate and Health" in 1999, and "Weather, Oceans and Human Activity" in 1998.
In the circumstances, it was very easy to chose a theme for World Meteorological Day this year: it is "WMO - 50 Years of Service".