1999–2000 South-West Indian Ocean cyclone season
The 1999–2000 South-West Indian Ocean tropical cyclone season was the first on record in which two storms – Leon–Eline and Hudah – struck Mozambique at tropical cyclone intensity, or with maximum sustained winds of at least 120 km/h (75 mph). The most notable storm of the season was Eline, which was the longest-lasting storm on record in the basin. It lasted for 29 days while traversing the southern Indian Ocean, making the strongest landfall in decades along eastern Madagascar in late February. The storm was the first in a series of three storms that struck the country in early 2000, along with Gloria in March and Hudah in April. Collectively, the three storms killed at least 316 people. The season started on November 1, 1999, and ended for most of the basin on April 30, 2000; for Mauritius and the Seychelles, the season continued until May 15. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin;
1986–87 South-West Indian Ocean cyclone season
During the season, the Météo-France office (MFR) on Réunion island issued warnings in tropical cyclones within the basin. Using satellite imagery from National Oceanic and Atmospheric Administration, the agency estimated intensity through the Dvorak technique, and warned on tropical cyclones in the region from the coast of Africa to 90° E, south of the equator. The World Meteorological Organization would later label the MFR as a Regional Specialized Meteorological Center in 1993. The Joint Typhoon Warning Center (JTWC), which is a joint United States Navy – United States Air Force task force, also issued tropical cyclone warnings for the southwestern Indian Ocean. The season's five named storms and one tropical cyclone – a storm attaining maximum sustained winds of at least - were both below the average of nine and five, respectively. The MFR considered the tropical cyclone year to begin on August 1 and continue to July 31 of the following year. There was an ongoing El Niño by December, and by January, the monsoon was weaker than normal across the region. This caused below normal thunderstorm activity in February.
In addition to the storms classified by the MFR, the JTWC tracked four additional storms. The first, classified as Tropical Cyclone 01S, formed on August 1 in the northeastern portion of the basin, an infrequent event for the time of year. The storm moved westward with peak 1 minute winds of 85 km/h (50 mph). It gradually weakened, dissipating on August 3 near Diego Garcia. The JTWC also tracked a short-lived storm in January that they classified as Tropical Cyclone 06S. The storm formed on January 7 in the eastern portion of the basin near Diego Garcia, and reached winds of 85 km/h (50 mph) while moving southeastward. After stalling on January 9, the system dissipated three days later. Later, the agency monitored Tropical Cyclone 26S beginning on April 24. The storm formed south of Diego Garcia and moved in a counterclockwise direction, first to the southeast and later to the north. After reaching peak 1 minute winds of 85 km/h (50 mph), the storm dissipated on April 26. The final storm tracked by the agency originated on June 25 in the far northeastern portion of the basin between Diego Garcia and the Cocos Islands. It moved slowly to the southwest, failing to intensify beyond winds of 65 km/h (40 mph). Turning to the southeast, the system dissipated on June 27.