The basin is defined as the area west of 90°E and south of the Equator in the Indian Ocean, which includes the waters around Madagascar westward to the east coast of Africa.

Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion (MFR),[nb 1] as well as by the Joint Typhoon Warning Center (JTWC).

The agency estimated intensity through the Dvorak technique,[4] and warned on tropical cyclones in the region from the coast of Africa to 90° E, south of the equator.

[4] The remainder of the list was Laura, Monette, Neige, Octavie, Pamela, Rosita, Stella, Tasiana, Vigonia, Wendy, and Yolande.

[7] On September 25, a low-pressure area persisted between the Cocos Islands and Sumatra in the Australian region, east of 90° E. It moved southwestward into the south-west Indian Ocean due to a large ridge to the south.

In addition, the JTWC estimated the system attained 1-minute sustained peak winds of 120 km/h (75 mph) on September 28, the equivalent of a minimal hurricane.

[8] Subsequently, increased wind shear incurred weakening due to a trough to the south, which stripped the convection from the center.

Following steady intensification, the disturbance became Tropical Storm Babie on October 19,[4] reaching peak winds of 70 km/h (45 mph).

A circulation developed within the system on January 13 about 400 km (250 mi) southwest of Diego Garcia, and at that time it became a tropical disturbance.

Moving across Réunion, Colina produced strong wind gusts in the mountainous peaks, reaching 205 km/h (127 mph) at La Plaine-des-Palmistes.

[11] On nearby Mauritius, Colina dropped about 106 mm (4.2 in) of rainfall and produced wind gusts of 114 km/h (71 mph); the storm did not cause much damage there.

The system intensified into Tropical Storm Dessilia on January 19,[4] reaching peak 10 minute winds of 95 km/h (60 mph) at 12:00 UTC on the next day.

Initially, it appeared that Colina absorbed Dessilia once the latter storm emerged from the Madagascar coastline, although they remained separate systems.

[12] Increased wind shear weakened the convection, and the storm dissipated on January 24; the next day, the remnants were absorbed by a passing cold front.

The next day, a low-pressure area formed between the Chagos Archipelago and Diego Garcia, and on January 19 the system developed into a tropical disturbance after convection increased.

On the next day, the JTWC estimated the cyclone attained peak winds of 205 km/h (125 mph),[13] after Edwina developed a well-defined 75 km (47 mi) wide eye.

[4] On January 26, the MFR estimated that the cyclone reached peak 10-minute winds of 170 km/h (105 mph),[13] making Edwina the strongest storm of the season.

On January 29, Edwina ceased existing as a tropical system, although its remnants persisted several more days, affecting Île Amsterdam in the south-central Indian Ocean on February 2.

[4] A large low-pressure area persisted on February 11 across northern Madagascar, centered near Cape Masoala along the country's eastern coast.

Moving southward and later southeastward due to a trough, the system developed into a tropical disturbance on February 12 and slowly organized.

[6] The MFR upgraded the system to Tropical Storm Finella on February 14 after an eye feature developed within the central dense overcast.

The convection reorganized, developing a ragged eye with circular rainbands, and the system intensified into Tropical Storm Gracia on February 22.

Shortly thereafter, the convection rapidly disintegrated as Gracia made landfall on northwestern Madagascar near Besalampy, dissipating early on February 23.

[16] After passing about 50 km (30 mi) north of Juan de Nova island, Ionia progressed southeastward and approached the western Madagascar coastline.

[4] After a period of inactivity lasting slightly less than a month, the tropics became active again in early April when the ITCZ spawned an area of convection in the northeastern portion of the basin.

Around the same time, the JTWC estimated peak 1-minute winds of 230 km/h (145 mph),[18] which was tied for the strongest system in the southern hemisphere in the cyclone year by the agency.

The first was Tropical Depression C1, that originated from the ITCZ in the northeastern portion of the basin from a small area of convection on November 24.

It moved westward with pulsating convection around the center, failing to organize due to the presence of wind shear.

On December 4, the system organized into a tropical disturbance, and three days later it passed about 400 km (250 mi) north of the northern tip of Madagascar.

[6] On December 24, a cold front exited the southern African coastline, accompanied by a low-pressure area that moved into the Mozambique Channel.