2005–06 South-West Indian Ocean cyclone season
The 2005–06 South-West Indian Ocean cyclone season was the fifth least-active on record. The Météo-France office on the island of Réunion tracked 13 tropical disturbances, of which six intensified into a moderate tropical storm. Three of these systems proceeded to attain tropical cyclone status – reaching 10 minute maximum sustained winds of at least 120 km/h (75 mph). The American-based Joint Typhoon Warning Center also tracked eight storms in the basin. Activity was below normal due to a powerful Walker circulation, which increased convection over the neighboring Australian basin, but suppressed activity in the western Indian Ocean. As a result, most of the storms developed near or entered from the Australian basin, crossing 90°E to enter the South-West Indian Ocean.
A series of four short-lived systems occurred from September to November in the northeastern portion of the basin. These were followed by the first named storm – Alvin – which was renamed after it crossed from the Australian region as Tropical Cyclone Bertie in late November. After another short-lived disturbance in late December, there was a tropical disturbance in the Mozambique Channel in January that killed 26 people when it brought heavy rainfall to Mozambique. Later in the month, Tropical Cyclone Boloetse took an erratic track across Madagascar, killing six people when it brushed the island's southwest coast. In February, there was a small, short-lived unnamed tropical storm that presented difficulties to warning agencies in determining its structure. Intense Tropical Cyclone Carina was the strongest system of the season, attaining peak 10 minute winds of 205 km/h (125 mph) in the open waters of the eastern portion of the basin. Sprawling Tropical Storm Diwa brought six months' worth of rainfall to the drought-ridden island of Réunion, reaching 2,943 mm (115.9 in) in the mountainous peaks. The rains led to flooding and landslides that killed 10 people directly or indirectly. Two of the deaths occurred when a saturated cliff collapsed onto a coastal road. The final storm, Elia, dissipated on April 17 after previously entering from the Australian basin.