South-West Indian Ocean tropical cyclone

In the south-west Indian Ocean, tropical cyclones form south of the equator and west of 90° E to the coast of Africa.

Satellite image of Cyclone Batsirai, the strongest tropical cyclone to strike Madagascar since Cyclone Enawo in 2017.

Warnings and nomenclature

In 1946, Réunion's first airstrip opened, then called Gillot, and now called Roland Garros Airport. In 1950, the first meteorological station on the island opened at the airport, operated by Météo-France (MFR). The agency began publishing annual reviews in the 1962–63 season. Each year, the Météo-France office (MFR) based on Réunion island issues warnings on tropical cyclones within the basin, which is defined as the waters of the Indian Ocean from the coast of Africa to 90° E, south of the equator. The agency issues the warnings as part of its role as a Regional Specialized Meteorological Center, designated as such in 1993 by the World Meteorological Organization. Intensities are estimated through the Dvorak technique, which utilizes images from satellites by the American National Oceanic and Atmospheric Administration.[1][2][3][4]

The Joint Typhoon Warning Center – a joint United States Navy – United States Air Force task force – also issues tropical cyclone warnings for the region.[5] Wind estimates from Météo-France and most other basins throughout the world are sustained over 10 minutes, while estimates from the United States-based Joint Typhoon Warning Center are sustained over 1 minute. 1-minute winds are about 1.12 times the amount of 10-minute winds.[6]

If a tropical storm in the basin strengthens to attain 10 minute sustained winds of at least 118 km/h (73 mph), the MFR classifies it as a tropical cyclone, equivalent to a hurricane or typhoon (a use of "tropical cyclone" which is more restrictive than the usual definition).[7]

History of the basin

The first storm in the MFR database of the basin originated on January 11, 1848. In January 1960, the first named storm was Alix, and each subsequent year had a list of storm names. Beginning in 1967, satellites helped locate cyclones in the basin, and in the following year, the MFR began estimating storm intensities from the satellite images. By 1977, the agency was using the Dvorak technique on an unofficial basis, but officially adopted it in 1981. Originally, the basin only extended to 80° E, and while it was extended eastward to the current 90° E, a lack of satellite imagery initially made data uncertain east of 80° E. The World Meteorological Organization designated the MFR as a Regional Tropical Cyclones Advisory Centre in 1988, and upgraded it to a Regional Specialized Meteorological Center in 1993. In May 1998, two Europe-based Meteosat satellites began providing complete coverage of the basin. On July 1, 2002, the MFR shifted the cyclone year to begin on this date and end on June 30 of the following year; previously, the cyclone year began on August 1 and ended on the subsequent July 31. In 2003, the MFR extended their area of warning responsibility to 40°S, having previously been limited to 30°S.[2] During 2011, MFR started a reanalysis project of all tropical systems between 1978 and 1998, with methods such as a Dvorak technique reanalysis and use of microwave imagery.[8] Preliminary results from this reanalysis project include correcting an increasing trend in the number of very intense tropical cyclones in the basin since 1978.[8] This also revealed a seemingly systematic underestimation of tropical cyclone intensities in the past.[8]

Statistics

From the 1980–81 to the 2010–11 season, there was an average of 9.3 tropical storms each year in the basin. A tropical storm has 10-minute winds of at least 65 km/h (40 mph). There are an average of five storms that become tropical cyclones, which have 10-minute winds of at least 120 km/h (75 mph).[9] As of 2002, there was an average of 54 days when tropical systems were active in the basin, of which 20 had tropical cyclones active, or a system with winds of over 120 km/h (75 mph). The median start date for the season was November 17, and the median end date was April 20.[1]

Climatology
Tracks of storms in the basin from 1980 to 2005

Generally, the monsoon does not cross into the Mozambique Channel until December; as a result, storms rarely form there before that time.[1] From 1948 to 2010, 94 tropical systems developed in the small body of water, of which about half made landfall.[10] Occasionally, small storms form in the Mozambique Channel that resemble Mediterranean tropical cyclones or storms in the northeastern Atlantic Ocean; these systems are well-organized but have weaker convection than typical tropical cyclones, and originate over cooler than normal water temperatures of less than 26 °C (79 °F). A survey in 2004 conducted by weather expert Gary Padgett found meteorologists split whether these storms should be classified as tropical or subtropical.[11]

In an average year, ten tropical depressions or storms strike Madagascar, and most generally do not cause much damage.[12] Occasionally, storms or their remnants enter the interior of southeastern Africa, bringing heavy rainfall to Zimbabwe.[13]

Seasons
Historical storm formation by month between 1990 and 2020
10
20
30
40
50
60
70
80
90
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  •   Very intense tropical cyclone
  •   Intense tropical cyclone
  •   Tropical cyclone
  •   Severe tropical storm
  •   Moderate tropical storm
  •   Tropical depression
  •   Tropical disturbance

Before 1900
Main article: List of South-West Indian Ocean cyclones before 1900

1900–1950
Main article: 1900–1950 South-West Indian Ocean cyclone seasons

1950–1959
Main article: 1950s South-West Indian Ocean cyclone seasons

1959
SeasonTDTCStrongest
storm		DeathsDamage
USD		Notes and
References
1959–196068Carol48

1960s
SeasonTDTCStrongest
storm		DeathsDamage
USD		Notes and
References
1960–196161Doris
1961–1962145Daisy
Maud
1962–1963104 TC  Delia
1963–1964124 ITC  Giselle
1964–1965141 TC  Freda
1965–1966175 ITC  Ivy3
1966–1967132 TC  Gilberte
1967–196884 ITC  Georgette
 ITC  Janine		38
1968–196984 TC  Dany
 TC  Helene		82
1969–1970138 VITC  Jane30

1970s
SeasonTDMTSTCITCVITCStrongest
storm		DeathsDamage
USD		Notes and
References
1970–19711611840 ITC  Maggie-Muriel32
1971–197297210 ITC  Fabienne7
1972–19731311421 VITC  Lydie11
1973–197487100 TC  Deidre-Delinda
1974–1975106200 TC  Gervaise9
1975–197686110 ITC  Terry-Danae
1976–197798310 ITC  Jack-Io301
1977–19781412210 ITC  Aurore2
1978–1979106420 ITC  Celine74
1979–19801111420 ITC  Viola-Claudette30

1980s
SeasonTDMTSTCITCStrongest
storm		DeathsDamage
USD		Notes and
References
1980–81121032 VITC  Florine
1981–82141052 ITC  Chris-Damia100$250 million
1982–836300 STS  Bemany and Elinah33$23 million
1983–84141144 ITC  Andry, Bakoly, Annette-Jaminy, and Kamisy356$496 million
1984–859910 TC  Helisaonina0Unknown
1985–86131351 ITC  Erinesta99$150 million
1986–8710810 TC  Daodo10$2 million
1987–88111141 ITC  Gasitao100$10 million
1988–89121160 TC  Leon-Hanitra and Krissy11$217 million
1989–909951 ITC  Walter-Gregoara46$1.5 million

1990s
SeasonTDMTSTCITCVITCStrongest
storm		DeathsDamage
USD		Notes and
References
1990–91117300 TC  Bella88
1991–921411310 ITC  Harriet-Heather2
1992–931811420 ITC  Edwina20[A 1][14]
1993–941814840 ITC  Geralda558
1994–952011530 ITC  Marlene[15]
1995–962111630 ITC  Bonita11[16]
1996–972112530 ITC  Daniella311$50 million
1997–98165100 TC  Anacelle88
1998–99146220 ITC  Evrina2
1999–00149431 VITC  Hudah1,073$800 millionThe second deadliest season on record.[17]

2000s
SeasonTDMTSTCITCVITCStrongest
storm		DeathsDamage
USD		Notes and
References
2000–01116420 ITC  Ando4[A 1][18]
2001–021511951 VITC  Hary52$287 million[19]
2002–031412730 ITC  Kalunde169$6.7 million[A 1]
2003–041510531 VITC  Gafilo396$250 millionFourth deadliest season on record, also features the most intense storm in the basin, Gafilo.[20][21]
2004–051810431 VITC  Juliet253[21]
2005–06136320 ITC  Carina75[22][23]
2006–071510760 ITC  Dora and Favio188$337 million[A 1][23]
2007–081513640 ITC  Hondo123$38.1 million[23]
2008–091210220 ITC  Fanele and Gael30[24]
2009–10169541 VITC  Edzani40[A 1][24][25]
1449752344Gafilo1,339≥$919 million

2010s
SeasonTDMTSTCITCVITCStrongest
storm		DeathsDamage
USD		Notes and
References
2010–1193200 TC  Bingiza34[A 1][26]
2011–121410320 ITC  Funso164[A 1][26]
2012–131110730 ITC  Felleng35$46 million
2013–141511552 VITC  Hellen11$89.2 million
2014–151411432 VITC  Bansi111$46.4 million
2015–1688331 VITC  Fantala13$4.5 millionFeatures the strongest storm by windspeed recorded in the basin, Fantala.[27]
2016–1775310 ITC  Enawo341$137 million
2017–1898630 ITC  Cebile108$38.2 million
2018–19151511100 ITC  Kenneth1,672≥$3.65 billionMost active, costliest, and deadliest season on record
2019–201210631 VITC  Ambali45$25 million
1128949326Fantala2,244≥$2.7 billion

2020s
SeasonTDMTSTCITCVITCStrongest
storm		DeathsDamage
USD		Notes and
References
2020–211612722 VITC  Faraji
 VITC  Habana		56$11 millionFeatures two very intense tropical cyclones named in the basin.
Record third consecutive season for a storm to develop before the official start (Alicia).
2021–221312550 ITC  Batsirai376>$312 millionLatest start to an SWIO season, fifth deadliest season, and second costliest season
2022–23109532 VITC  Darian1,483Features two very intense tropical cyclones named in the Australian Region.
Features Freddy, the longest lasting tropical cyclone ever recorded.
Third deadliest season.
39331794Darian1,912>$323 million

See also

Notes
  1. Number of tropical storms includes one subtropical depression that had winds above 65 km/h (40 mph).

References
  1. "Cyclone Season 2001–2002". RSMC La Reunion. Meteo-France. Retrieved April 28, 2013.
  2. Philippe Caroff; et al. (June 2011). Operational procedures of TC satellite analysis at RSMC La Reunion (PDF) (Report). World Meteorological Organization. Archived from the original (PDF) on 2014-10-06. Retrieved 2014-01-11.
  3. "Aéroport de la Réunion Roland Garros".
  4. Isabelle Mayer Jouanjean (2011). Lîle de La Réunion sous l'œil du cyclone au XXéme siécle (PDF) (Report) (in French). Université de la Réunion.
  5. Annual Tropical Cyclone Report (PDF) (Report). Joint Typhoon Warning Center. p. iii, 218, 240. Retrieved 2014-01-11.
  6. Chris Landsea (2006-04-21). "Subject: D4) What does "maximum sustained wind" mean? How does it relate to gusts in tropical cyclones?". Frequently Asked Questions. Hurricane Research Division. Retrieved 2017-08-06.
  7. Chris Landsea (2001-07-15). "Subject: A1) What is a hurricane, typhoon, or tropical cyclone?". Frequently Asked Questions. Hurricane Research Division. Retrieved 2015-02-20.
  8. Philippe Caroff (October 23, 2015). Review of recent (2012-2015) main activities and achievements at RSMC La Reunion (docx). Eighth tropical cyclone technical coordination meeting (TCM-8). World Meteorological Organization. Retrieved November 1, 2015.
  9. Chris Landsea; Sandy Delgado (2014-05-01). "Subject: E10) What are the average, most, and least tropical cyclones occurring in each basin?". Frequently Asked Questions. Hurricane Research Division. Retrieved 2014-10-13.
  10. Corene J. Matyas (2014-04-07). "Tropical cyclone formation and motion in the Mozambique Channel". International Journal of Climatology. 35 (3): 375–390. Bibcode:2015IJCli..35..375M. doi:10.1002/joc.3985. S2CID 130753010.
  11. "June 2004 Monthly Global Tropical Cyclone Summary". Gary Padgett. Retrieved 2015-02-20.
  12. Cyclone Rehabilitation Project (PDF) (Report). World Bank. 1992-05-11. Retrieved 2015-02-20.
  13. A. Mhizha; M. Musariri; E. Madamombe; Tererai (2012-01-23). Preliminary Water Resources Assessment for the Limpopo River Basin (PDF) (Report). University of Zimbabwe. Archived from the original (PDF) on 2015-04-02. Retrieved 2015-03-05.
  14. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 1992–1993 (Report). Meteo-France. Retrieved December 20, 2012.
  15. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 1994–1995 (Report). MeteoFrance. Retrieved December 20, 2012.
  16. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 1995–1996 (Report). Meteo-France. Retrieved December 20, 2012.
  17. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 1999–2000 (Report). Meteo-France. Retrieved December 20, 2012.
  18. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 2000–2001 (Report). Meteo-France. Retrieved November 26, 2012.
  19. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 2001–2002 (Report). Meteo-France. Retrieved November 26, 2012.
  20. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 2003–2004 (Report). Meteo-France. Retrieved December 20, 2012.
  21. RA I Tropical Cyclone Committee for the South-West Indian Ocean (2006-06-16). RA I Tropical Cyclone Committee for the South-West Indian Ocean Seventeenth Session (PDF) (Final Report). World Meteorological Organisation. pp. 30–32. Retrieved December 20, 2012.
  22. RSMC La Reunion Tropical Cyclone Centre. Cyclone Season 2005–2006 (Report). Meteo-France. Retrieved December 20, 2012.
  23. RA I Tropical Cyclone Committee for the South-West Indian Ocean (2010-09-15). RA I Tropical Cyclone Committee for the South-West Indian Ocean Eighteenth Session (PDF) (Final Report). World Meteorological Organisation. p. 31. Retrieved December 20, 2012.
  24. RA I Tropical Cyclone Committee for the South-West Indian Ocean (August 3, 2011). RA I Tropical Cyclone Committee for the South-West Indian Ocean Nineteenth Session (PDF) (Final Report). World Meteorological Organisation. pp. 5–8. Retrieved December 20, 2012.
  25. Padgett, Gary (1997–2011). "Monthly Global Tropical Cyclone Summaries". Archived from the original on February 18, 2020. Retrieved July 25, 2012. Alt URL
  26. RA I Tropical Cyclone Committee for the South-West Indian Ocean (December 3, 2012). RA I Tropical Cyclone Committee for the South-West Indian Ocean Twentieth Session (PDF) (Final Report). World Meteorological Organisation. pp. 2, 7, 8. Archived (PDF) from the original on February 22, 2014. Retrieved December 20, 2012.
  27. $4.5 million in damages from cyclone that hit remote Seychellois island, World Bank says (Seychelles News Agency, May 17, 2016)
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.