| Basin: | SWI |
| Year: | 1980 |
| Track: | 1979-1980 South-West Indian Ocean cyclone season summary.jpg |
| First Storm Formed: | August 30, 1979 |
| Last Storm Dissipated: | March 20, 1980 |
| Strongest Storm Name: | Viola-Claudette |
| Strongest Storm Pressure: | 930 |
| Strongest Storm Winds: | 110 |
| Average Wind Speed: | 10 |
| Total Depressions: | 11 |
| Total Storms: | 11 |
| Total Hurricanes: | 4 |
| Total Intense: | 2 |
| Fatalities: | 30 |
| Damages: | 342 |
| Five Seasons: | 1977–78, 1978–79, 1979–80, 1980–81, 1981–82 |
| Australian Season: | 1979–80 Australian region cyclone season |
| South Pacific Season: | 1979–80 South Pacific cyclone season |
The 1979–80 South-West Indian Ocean cyclone season was an above-average cyclone season, and is most notable for featuring the wettest tropical cyclone ever recorded, Cyclone Hyacinthe. The season officially ran from November 1, 1979, to April 30, 1980.
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bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/11/1979 till:30/11/1979 text:November from:01/12/1979 till:31/12/1979 text:December from:01/01/1980 till:31/01/1980 text:January from:01/02/1980 till:28/02/1980 text:February from:01/03/1980 till:31/03/1980 text:March from:01/04/1980 till:30/04/1980 text:April
TextData = pos:(525,23) text:"(For further details, please see" pos:(672,23) text:"scales)"
| Basin: | Aus |
| 10-Min Winds: | 50 |
| Track: | Tony 1979 track.png |
| Pressure: | 990 |
| Formed: | August 27 |
| Dissipated: | August 31 |
On 26 August, the BoM reported that a tropical low had developed on a shear line about 1300km (800miles) to the northwest of Cocos Island.[1] Over the next couple of days the depression gradually developed further before at 1800 UTC on 27 August, TCWC Perth estimated that it had become a tropical cyclone and named it Tony.[1] During the next couple of days, the system moved towards the west-southwest before on 29 August it reached its peak intensity of 50kn and a peak pressure of 990abbr=onNaNabbr=on as it approached the edge of TCWC Perth's area of responsibility.[1] During the next day, Tony moved into the South West Indian Ocean and weakened gradually before it dissipated during 31 August.[1] Neither the Mauritius or Reunion meteorological services monitored Tony as a tropical cyclone while it was active, while it was not included in the JTWC's analysis of the season.[1] [2] [3]
| Basin: | SWI |
| Track: | Albine 1979 track.png |
| Formed: | November 25 |
| Dissipated: | December 6 |
| 10-Min Winds: | 105 |
| 1-Min Winds: | 90 |
| Pressure: | 960 |
Albine existed from 25 November to 6 December.
| Basin: | SWI |
| Track: | Viola-Claudette 1979 track.png |
| Formed: | December 18 (Crossed 80°E) |
| Dissipated: | December 28 |
| 10-Min Winds: | 115 |
| 1-Min Winds: | 110 |
| Pressure: | 955 |
Cyclone Viola entered the basin on December 18 from the Australian region, whereupon it became Cyclone Claudette.[4] After passing southeast of St. Brandon, Claudette struck Mauritius on December 22, producing wind gusts of 221km/h. The storm caused 5 fatalities, 257 injuries, and US$175 million in damage on the island. About 5,000 houses were destroyed or severely damaged. Effects on neighboring Réunion were limited to 79km/h wind gusts and some rainfall.[5] [6] [7] [8]
| Basin: | SWI |
| Track: | Berenice 1979 track.png |
| Formed: | December 15 |
| Dissipated: | December 21 |
| 10-Min Winds: | 35 |
| 1-Min Winds: | 35 |
| Pressure: | 1000 |
Berenice existed from 15 December to 21 December.
| Basin: | SWIO |
| Type1: | swiodepression |
| Track: | Wilf-Danitza 1979 track.png |
| Formed: | December 23 |
| Dissipated: | January 3 |
| 10-Min Winds: | 29 |
| 1-Min Winds: | 35 |
| Pressure: | 1000 |
Wilf-Danitza existed from 23 December 1979, to 3 January 1980.
| Basin: | SWI |
| Track: | Hyacinthe 1980 track.png |
| Formed: | January 15 |
| Dissipated: | January 31 |
| 10-Min Winds: | 90 |
| 1-Min Winds: | 70 |
| Pressure: | 960 |
See main article: Cyclone Hyacinthe. Hyacinthe formed on January 15, 1980, to the northeast of Mauritius in the southern Indian Ocean. Initially it moved to the west-southwest, and while slowly intensifying it passed north of the French overseas department of Réunion. On January 19, Météo-France estimated that the storm had intensified to a tropical cyclone. Hyacinthe looped to the south of eastern Madagascar and weakened, although it restrengthened after turning to the east. The storm executed another loop to the southwest of Réunion, passing near the island for a second and later third time. Hyacinthe became extratropical on January 29 after turning southward, dissipating two days later.
Tropical Cyclone Hyacinthe set several worldwide tropical cyclone rainfall records in Réunion in the Southwestern Indian Ocean, including a peak total of 5678 mm (223.5 inches).[9] For twelve days, Hyacinthe dropped torrential rainfall on Réunion; nearly all of the island received more than 1 m (3.3 ft) of precipitation. Over a 15‑day period from January 14 to January 28, 6083mm of rainfall were recorded at Commerson's Crater, a volcano. The heaviest rainfall occurred through a process called orographic lift in the mountainous interior, leading to hundreds of landslides. Widespread floods washed out roads and isolated three villages. Hyacinthe caused heavy damage to crops and damaged or destroyed 2,000 houses. Losses from the storm totaled $167 million (1980 USD, 676 million francs), and 25 people were killed.
| Basin: | SWI |
| Track: | Jacinthe 1980 track.png |
| Formed: | February 1 |
| Dissipated: | February 7 |
| 10-Min Winds: | 100 |
| 1-Min Winds: | 100 |
| Pressure: | 955 |
Jacinthe existed from 1 February to 7 February. On February 3, the cyclone passed between Mauritius and Rodrigues, producing wind gusts of 117km/h and 119km/h on the respective islands.[10]
| Basin: | SWI |
| Track: | Kolia 1980 track.png |
| Formed: | February 25 |
| Dissipated: | March 13 |
| 10-Min Winds: | 60 |
| 1-Min Winds: | 60 |
| Pressure: | 985 |
Kolia existed from 25 February to 13 March. The storm executed two loops near the Mascarene Islands, bringing the storm between Réunion and Mauritius twice. Wind gusts reached 80km/h on Mauritius.[11]
| Basin: | SWI |
| Track: | Laure 1980 track.png |
| Formed: | March 8 |
| Dissipated: | March 17 |
| 10-Min Winds: | 90 |
| 1-Min Winds: | 100 |
| Pressure: | 965 |
Laure existed from 8 March to 17 March. On March 13, the cyclone passed just east of Mauritius, producing wind gusts of 109km/h and 65.7mm of rainfall.[12]
| Basin: | SWI |
| Track: | 22S 1980 track.png |
| Formed: | March 14 |
| Dissipated: | March 20 |
| 10-Min Winds: | 45 |
| 1-Min Winds: | 40 |
22S existed from 14 March to 20 March.