South-West Indian Ocean tropical cyclone

In the south-west Indian Ocean, tropical cyclones form south of the equator and west of 90° E to the coast of Africa.

Each year, the Météo-France office (MFR) based on Réunion island issues warnings on tropical cyclones within the basin, which is defined as the waters of the Indian Ocean from the coast of Africa to 90° E, south of the equator. The agency issues the warnings as part of its role as a Regional Specialized Meteorological Center, designated as such in 1993 by the World Meteorological Organization. Intensities are estimated through the Dvorak technique, which utilizes images from satellites by the American National Oceanic and Atmospheric Administration.

The Joint Typhoon Warning Center – a joint United States Navy – United States Air Force task force – also issues tropical cyclone warnings for the region. Wind estimates from Météo-France and most other basins throughout the world are sustained over 10 minutes, while estimates from the United States-based Joint Typhoon Warning Center are sustained over 1 minute. 1-minute winds are about 1.14 times the amount of 10-minute winds.

If a tropical storm in the basin strengthens to attain 10 minute sustained winds of at least 120 km/h (75 mph), the MFR classifies it as a tropical cyclone, equivalent to a hurricane or typhoon (a use of "tropical cyclone" which is more restrictive than the usual definition).

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