1999–2000 South-West Indian Ocean cyclone season
The same monsoon trough that spawned Connie also produced an area of convection southeast of Diego Garcia on January 28. The circulation slowly organized, and the MFR classified it as a tropical disturbance on January 30. A nearby trough steered the system southeastward initially and later to the southwest. On January 31, the system became a tropical depression, and later Moderate Tropical Storm Damienne the next day, reaching peak winds of 65 km/h (40 mph). Also on February 1, the JTWC initiated warnings on Tropical Cyclone 10S, which estimated 1‑minute winds of 95 km/h (60 mph). Increased wind shear removed the convection on February 2, causing marked weakening, and prompting the JTWC to discontinue advisories that day. This was despite forecasts of strengthening to near tropical cyclone status. As a weak tropical disturbance, Damienne turned to a rapid westward motion, passing north of Rodrigues and Tromelin. The circulation dissipated on February 7 off the northeast coast of Madagascar.
On February 1, a low-pressure area formed within the monsoon trough to the south of Indonesia, which would eventually become Tropical Cyclone Leon in the Australian basin, as well as Tropical Cyclone 11S according to JTWC. The storm tracked westward across much of the Indian Ocean, fluctuating in strength due to changes in the atmosphere. After crossing 90° E, the MFR began tracking the system as Tropical Storm Eline on February 8. The storm continued westward across the Indian Ocean and intensified greatly as it approached the east coast of Madagascar. Late on February 17, Eline made landfall near Mahanoro with 10‑minute winds of 165 km/h (105 mph), making it the strongest storm to hit the country in several decades. The storm rapidly weakened over land, but restrengthened in the Mozambique Channel to reach peak 10‑minute winds of 185 km/h (115 mph). On February 22, Eline made landfall about 80 km (50 mi) south of Beira, Mozambique near peak intensity and quickly weakened over land. The well-defined circulation moved across southern African, finally dissipating over eastern Namibia on February 29. Throughout its duration, Leon–Eline lasted 29 days, a record longevity for a storm in the south-west Indian Ocean. The track was over 11,000 km (6,800 mi), or about 25% of the Earth's circumference.
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.