2011–12 South-West Indian Ocean cyclone season
Encyclopedia
The 2011–12 South-West Indian Ocean cyclone season is an event in the annual cycle of tropical cyclone
formation. It began on November 15, 2011, and will end on April 30, 2012, with the exception for Mauritius
and the Seychelles
, for which it will end on May 15, 2012. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin, which is west of 90°E
and south of the Equator
. Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion
.
on La Réunion Island
, France (RSMC La Réunion) are usually assigned a name. However it is the Sub-Regional Tropical Cyclone Advisory Centers in Mauritius and Madagascar who name the systems. The Sub-Regional Tropical Cyclone Advisory Center in Mauritius names the storm should it intensify into a moderate tropical storm between 55°E
and 90°E
, if the storm should intensify into a moderate tropical storm between 30°E
and 55°E
then the Sub-Regional Tropical Cyclone Advisory Center in Madagascar assigns the appropriate name to the storm. For the final year, tropical cyclones that move into this region from the Australian region
will be renamed by the Sub-Regional Tropical Cyclone Advisory Center in Mauritius, however tropical cyclones moving into the Australian region will not be renamed. New name lists are used every year, whilst a name is normally only used once so thus no names are retired.
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
formation. It began on November 15, 2011, and will end on April 30, 2012, with the exception for Mauritius
Mauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
and the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, for which it will end on May 15, 2012. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin, which is west of 90°E
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
and south of the Equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
. Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
.
Storm names
Within the South-west Indian Ocean Tropical Depressions and Subtropical Depressions that are judged to have 10-minute sustained windspeeds of 65 km/h, (40 mph) by the Regional Specialized Meteorological CenterRegional Specialized Meteorological Center
A Regional Specialized 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.-Tropical...
on La Réunion Island
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
, France (RSMC La Réunion) are usually assigned a name. However it is the Sub-Regional Tropical Cyclone Advisory Centers in Mauritius and Madagascar who name the systems. The Sub-Regional Tropical Cyclone Advisory Center in Mauritius names the storm should it intensify into a moderate tropical storm between 55°E
55th meridian east
The meridian 55° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
and 90°E
90th meridian east
The meridian 90° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole.The Ninety East Ridge is named after the meridian....
, if the storm should intensify into a moderate tropical storm between 30°E
30th meridian east
The meridian 30° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Turkey, Africa, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
and 55°E
55th meridian east
The meridian 55° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
then the Sub-Regional Tropical Cyclone Advisory Center in Madagascar assigns the appropriate name to the storm. For the final year, tropical cyclones that move into this region from the Australian region
2011–12 Australian region cyclone season
The 2011–12 Australian region cyclone season is an event in the ongoing cycle of tropical cyclone formation. It began on 1 November 2011, and it will end on 30 April 2012...
will be renamed by the Sub-Regional Tropical Cyclone Advisory Center in Mauritius, however tropical cyclones moving into the Australian region will not be renamed. New name lists are used every year, whilst a name is normally only used once so thus no names are retired.
See also
- List of Southern Hemisphere cyclone seasons
- Atlantic hurricane seasons: 20112011 Atlantic hurricane seasonThe 2011 Atlantic hurricane season is tied for the third most active season on record with 1887, 1995 and 2010. It began on June 1, 2011, and ended on November 30, 2011, however these dates conventionally delimit the period of each year when most tropical cyclones develop in the Atlantic basin...
, 2012 - Pacific hurricane seasons: 20112011 Pacific hurricane seasonThe 2011 Pacific hurricane season is an ongoing, annual cycle of tropical cyclone formation. The season officially started on May 15, 2011, for the eastern Pacific, and started on June 1, 2011, for the central Pacific, both of which ended on November 30, 2011. These dates conventionally...
, 2012 - Pacific typhoon seasons: 20112011 Pacific typhoon seasonThe 2011 Pacific typhoon season was the time of the year in which tropical cyclones form in the Western Pacific Ocean. The season ran throughout 2011 with most tropical cyclones forming between May and November. The scope of this article is limited to the Pacific Ocean to the north of the equator...
, 2012 - North Indian Ocean cyclone seasons: 20112011 North Indian Ocean cyclone seasonThe 2011 North Indian Ocean cyclone season is an event in the annual cycle of tropical cyclone formation. The North Indian Ocean cyclone season has no official bounds, but cyclones tend to form between April and December, with peaks in May and November...
, 2012 - 2011-12 Australian region cyclone season
- 2011-12 South Pacific cyclone season