The 1986–87 South-West Indian Ocean cyclone season was below average due to an ongoing El Niño and a weak monsoon that suppressed convection and storms.

The United States–based Joint Typhoon Warning Center (JTWC) followed four other storms in the basin, which is the waters of the Indian Ocean south of the equator and west of 90° E to the coast of Africa.

Tropical Storm Clotilda, the most damaging of the season, stalled near Réunion for three days, producing 2,723 mm (107.2 in) of rainfall at Bébourg.

Later, Daodo in March was the strongest storm of the season and the only to attain tropical cyclone status, reaching of 135 km/h (85 mph).

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 first, classified as Tropical Cyclone 01S, formed on August 1 in the northeastern portion of the basin,[2] an infrequent event for the time of year.

The storm formed on January 7 in the eastern portion of the basin near Diego Garcia, and reached winds of 85 km/h (55 mph) while moving southeastward.

[2] 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.

While near the island, the depression dropped heavy rainfall that broke 24‑hour totals at 10 locations, peaking at 600 mm (24 in) at Dos d'Âne.

The system intensified slightly afterward, although it turned to the east due to a ridge to the south and was no longer tracked after January 6.

[11] Toward the middle of January, the Intertropical Convergence Zone (ITCZ) spawned an area of convection between Diego Garcia and St.

[2] The system moved to the southeast, intensifying into tropical storm status on January 17, whereupon it was named Alinina by the Mauritius Meteorology Service.

Subsequently, the storm weakened, and Alinina turned sharply westward on January 20 due to a building ridge to the south.

[12][13] The ITCZ produced an area of convection north of the Mascarene Islands on February 5, organizing into a tropical disturbance that day about 590 km (365 mi) northeast of Rodrigues.

Moving quickly to the southwest, the disturbance passed west of Rodrigues on February 6, producing wind gusts of 117 km/h (73 mph) likely due to a localized vortex.

On the next day, the depression turned sharply to the east due to a nearby ridge, passing 350 km (215 mi) southeast of Mauritius.

Bemezava intensified into a moderate tropical storm on February 8, attaining peak 10 minute winds of 65 km/h (40 mph).

A weak ridge steered the storm back to the southwest, and on February 14, Clotilda struck northern Réunion at Sainte-Suzanne.

The storm accelerated to the southeast on the next day and maintained much of its intensity due to baroclinic interactions with a nearby anticyclone.

A ridge turned the storm eastward, and Elizabeta gradually weakened, deteriorating to tropical depression status by April 25.

However, the storm caused a large fall in barometric pressure at Fort Dauphin, with a drop of 8.3 mbar (0.25 inHg) over 24 hours.