A Regional Specialized Meteorological Centre (also Regional Specialized Meteorological Center and Regional Specialised Meteorological Centre) is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as part of the World Weather Watch.
There are six such meteorological centres and five regional Tropical Cyclone Warning Centres utilized for naming of tropical cyclones and the distribution of tropical cyclone advisories and warnings:
The majors tropical cyclones basins and the center in charge of each one.
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the Pacific Ocean (considered separately because tropical cyclones rarely form in the central Pacific), the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones (at least of Category 3 intensity).[3]
Northwestern Pacific Ocean: Tropical storms in this region often affect China, Japan, South Korea, Hong Kong, the Philippines, and Taiwan, as well as countries in Southeast Asia such as Vietnam and parts of Indonesia, plus numerous Oceanian islands. This is by far the most active basin, accounting for one-third of all tropical cyclone activity. The coast of China sees the most landfalling tropical cyclones worldwide.[4] The Philippines receives an average of 6-7 tropical cyclone landfalls per year.[5]
Northeastern Pacific Ocean: This is the second most active basin and has the highest number of storms per unit area. Storms that form here often affect western Mexico, and less commonly the Continental United States (in particular California), or northern Central America. No hurricane included in the modern database has made landfall in California; however, historical records from 1858 speak of a storm that brought San Diego winds over 75 mph/65 kts (marginal hurricane force), though it is not known if the storm actually made landfall.[6] Tropical storms in 1939, 1976 and 1997 brought gale-force winds to California.[6]
Northern Indian Ocean: This basin is divided into two areas, the Bay of Bengal and the Arabian Sea, with the Bay of Bengal dominating (5 to 6 times more activity). This basin's season has a double peak: one in April and May, before the onset of the monsoon, and another in October and November, just after.[10] The most deadly tropical cyclones have formed in this basin, including the 1970 Bhola cyclone that killed 200,000 people. Nations affected include India, Bangladesh, Sri Lanka, Thailand, Myanmar, and Pakistan. Rarely, a tropical cyclone that forms in this basin affects the Arabian Peninsula.
Southwestern Pacific Ocean: Tropical activity in this region largely affects Australia and Oceania. Tropical storms rarely reach the vicinity of Brisbane, Australia and into New Zealand, usually during or after extratropical transition.[11]
Southeastern Indian Ocean: Tropical activity in this region affects Australia and Indonesia. According to the Australian Bureau of Meteorology, the most frequently hit portion of Australia is between Exmouth and Broome in Western Australia.[12]
Southwestern Indian Ocean: Despite nearly a half century of historical data, research at Reunion Island into tropical cyclones has been a priority only since 1999, when Météo-France began assigning additional personnel for research purposes.[13] Cyclones forming in this area can affect Madagascar, Mozambique, Mauritius, Réunion, Comoros, Tanzania, and Kenya.[13]
Environmental Emergency Response Programme
There are eight meteorological centres for distribution of transport, deposition, and dispersion modeling, in the event of an environmental catastrophe that crosses international borders:[14]