2018–19 South-West Indian Ocean cyclone season

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2018–19 South-West Indian Ocean cyclone season
2018-2019 South-West Indian Ocean cyclone season summary.png
Season summary map
Seasonal boundaries
First system formedSeptember 13, 2018
Last system dissipatedSeason ongoing
Strongest storm
NameCilida
 • Maximum winds215 km/h (130 mph)
(10-minute sustained)
 • Lowest pressure940 hPa (mbar)
Seasonal statistics
Total disturbances12
Total depressions12
Total storms12
Tropical cyclones8
Intense tropical cyclones8 (record high)
Very intense tropical cyclones0
Total fatalities341 total
Total damage$45 million (2019 USD)
Related articles
South-West Indian Ocean tropical cyclone seasons
2016–17, 2017–18, 2018–19, 2019–20, 2020–21

The 2018–19 South-West Indian Ocean cyclone season is an ongoing and above-average event of the annual cycle of tropical cyclone and subtropical cyclone formation. It officially began on November 15, 2018, and will end on April 30, 2019, with the exception for Mauritius and the Seychelles, for which it will end on May 15, 2019. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion.

The first tropical cyclone was a moderate tropical storm that did not receive a name formed northeast Madagascar on September 13, 2018, two months before the official start of the season. Two cyclones formed in the month of November, with Intense Tropical Cyclone Alcide forming on November 5 and Severe Tropical Storm Bouchra. Two tropical cyclones formed in the month of December, Cilida and Kenanga. Intense Tropical Cyclone Kenanga crossed into the basin from the Australian region, retaining its name assigned by TCWC Jakarta. Two moderate tropical storms formed in January, Desmond and Eketsang. Four more intense tropical cyclones formed during February and March: Funani, Gelena, Haleh and Idai. In addition, Savannah crossed into the basin from the Australian basin as an intense tropical cyclone in March. Of these storms, all but Haleh and Savannah produced impacts on land with Idai resulting 314 deaths in Mozambique, Malawi and Madagascar. The season set a new record of eight intense tropical cyclones, surpassing the 2006-07 season, which was also the largest number recorded since the start of reliable satellite coverage in 1967.

Seasonal summary[edit]

Cyclone IdaiTropical cyclone scales#Comparisons across basins

The season officially began on November 15, 2018, and will end on April 30, 2019, with the exception for Mauritius and the Seychelles, for which it will end on May 15, 2019.

Systems[edit]

Moderate Tropical Storm 01[edit]

Moderate tropical storm (MFR)
Tropical storm (SSHWS)
01R 2018-09-16 0920Z.jpg 01R 2018 track.png
DurationSeptember 13 – September 17
Peak intensity75 km/h (45 mph) (10-min)  1004 hPa (mbar)

On September 13, a tropical depression formed to the southwest of Diego Garcia.[1] The system tracked west-southwestward, organizing slowly over marginally warm waters of 26–27 degrees Celsius and moderate wind shear.[2] On September 16, the tropical depression began to weaken after encountering unfavorable conditions. On September 17, both the MFR and the JTWC issued their final warnings, and the system dissipated.[3] In post-storm analysis, the system was upgraded into a moderate tropical storm, although it remained unnamed.[4]

Intense Tropical Cyclone Alcide[edit]

Intense tropical cyclone (MFR)
Category 3 tropical cyclone (SSHWS)
Alcide 2018-11-08 0656Z.jpg Alcide 2018 track.png
DurationNovember 5 – November 12
Peak intensity165 km/h (105 mph) (10-min)  965 hPa (mbar)

On November 6, a tropical depression formed well to the east-northeast of Madagascar.[5] The system continued to track generally west-southwestward into more favorable conditions for the next few hours, before strengthening into Moderate Tropical Storm Alcide later that day.[6] On November 7 at 06:00 UTC, Alcide strengthened into a tropical cyclone.[7] On November 8 at 06:00 UTC, Alcide strengthened into an intense tropical cyclone, with maximum 10-minute sustained winds of 90 knots (165 km/h; 105 mph).[8] It was downgraded to a tropical cyclone 6 hours later, however, due to cooler sea temperatures and generally less favorable conditions.[9] Alcide continued to weaken as it began an anticyclonic loop east of the northern tip of Madagascar, falling to tropical storm status at 12:00 UTC on November 9.[10] The system rapidly deteriorated thereafter, falling to tropical depression status at 00:00 UTC on November 11; Meteo-France discontinued advisories at noon that day.[11][12]

Severe Tropical Storm Bouchra[edit]

Severe tropical storm (MFR)
Tropical storm (SSHWS)
Bouchra 2018-11-11 0650Z.jpg Bouchra 2018 track.png
DurationNovember 9 (Entered basin) – November 19
Peak intensity95 km/h (60 mph) (10-min)  990 hPa (mbar)

A weak low-pressure system developed in the equatorial Indian Ocean in Météo-France's area of responsibility on November 1 and moved slowly eastwards over the following few days while showing little signs of intensification.[13] Late on November 9, as the developing precursor depression to Cyclonic Storm Gaja in the Bay of Bengal moved further away and the competing low-level airflow convergence associated with it diminished,[14] the system's structure organised sufficiently to be classified as a tropical disturbance by Météo-France.[15] Very shortly afterwards, the system crossed the 90th meridian east and entered the Australian region, where it was classified by TCWC Jakarta as a tropical depression on November 10 local time.[16] Later the same day, the JTWC assessed the developing low as having attained tropical storm status on the Saffir-Simpson Hurricane Wind Scale, and assigned the system the unofficial designation 04S.[17] A few hours later, at 10:00 UTC, the system moved back westwards and returned to the South-West Indian Ocean basin,[18] where it gained the name 'Bouchra' from Météo-France and underwent a twelve-hour phase of rapid intensification to severe tropical storm status.[19]

Over the following days, Bouchra fought increasingly unfavorable atmospheric conditions, and underwent a gradual weakening trend.[20] During this time, the cyclone proceeded to track in a slow cyclonic loop just to the west of the border of the Australian region in weak overall steering influences, and was often quasi-stationary.[20] After meandering here for a number of days, the system re-entered the Australian region late on November 12.[21] By this stage, the system had weakened significantly from its peak intensity, and was only at tropical depression strength.[22] The period of residence in the Australian basin proved to be short-lived once again, however, with Météo-France indicating that Ex-Tropical Storm Bouchra had returned to the far eastern part of their area of responsibility early on November 13.[21] In the early hours of November 14, the Australian Bureau of Meteorology noted that the system had crossed back into the Australian region basin.[23] However, on November 17, Bouchra crossed back over into the South-West Indian Ocean basin, as the storm began taking a southwestward trajectory.

Intense Tropical Cyclone Kenanga[edit]

Intense tropical cyclone (MFR)
Category 4 tropical cyclone (SSHWS)
Kenanga 2018-12-18 1942Z.jpg Kenanga 2018 track.png
DurationDecember 16 (Entered basin) – December 22
Peak intensity185 km/h (115 mph) (10-min)  942 hPa (mbar)

On December 14, a tropical low formed well southwest of Sumatra in the Australian region basin. After a period of strengthening, it received the name Kenanga as it tracked roughly southwestward. Continuing on this course, Kenaga entered the South-West Indian basin on December 16 and subsequently strengthened into an intense tropical cyclone, over the course of the next three days. Afterward, Kenanga dissipated on December 22.

Intense Tropical Cyclone Cilida[edit]

Intense tropical cyclone (MFR)
Category 4 tropical cyclone (SSHWS)
Cilida 2018-12-21 0640Z.jpg Cilida 2018 track.png
DurationDecember 16 – December 24
Peak intensity215 km/h (130 mph) (10-min)  940 hPa (mbar)

On December 16, Metro-France tracked a low-pressure area inside an area of possible tropical cyclone development. While tracking southwest, it then intensified to tropical storm status and then cyclone status. On December 23, it passed east of Mauritius, bringing beneficial rainfall and gusting winds that knocked down tree branches. It then turned southeast and weakened, later dissipating in the far southern reaches of the basin.[24][25]

Moderate Tropical Storm Desmond[edit]

Moderate tropical storm (MFR)
Tropical storm (SSHWS)
Desmond 2019-01-20 1115Z.jpg Desmond 2019 track.png
DurationJanuary 17 – January 22
Peak intensity65 km/h (40 mph) (10-min)  995 hPa (mbar)

A Tropical Depression formed on January 17. It intensified into a moderate tropical storm and received the name Desmond. It reached peak intensity as a moderate tropical storm with 65 km/h wind and a pressure on 995 mbar. total of 230 people were affected by Desmond, and 54 houses were destroyed by the storm.[26] The system dissipated on January 22.

Moderate Tropical Storm Eketsang[edit]

Moderate tropical storm (MFR)
Eketsang 2019-01-24 1050Z.jpg Eketsang 2019 track.png
DurationJanuary 22 – January 24
Peak intensity75 km/h (45 mph) (10-min)  993 hPa (mbar)

A Tropical Depression formed on January 22. By the next day, the system had intensified into Moderate Tropical Storm Eketsang, reaching peak intensity with 10-minute sustained winds of 75 km/h and a minimum central pressure of 993 mbar. The storm left 27 dead and 1 missing in Madagascar, mostly due to landslides.[27] the system dissipated on January 24.

Intense Tropical Cyclone Funani[edit]

Intense tropical cyclone (MFR)
Category 4 tropical cyclone (SSHWS)
Funani 2019-02-07 0915Z.jpg Funani 2019 track.png
DurationFebruary 3 – February 10
Peak intensity195 km/h (120 mph) (10-min)  940 hPa (mbar)

The threat of the storm prompted officials to cancel 6 flights on Rodrigues.[28]

Intense Tropical Cyclone Gelena[edit]

Intense tropical cyclone (MFR)
Category 4 tropical cyclone (SSHWS)
Gelena 2019-02-09 0627Z.jpg Gelena 2019 track.png
DurationFebruary 4 – February 14 (Exited basin)
Peak intensity205 km/h (125 mph) (10-min)  942 hPa (mbar)

Gelena was the second storm to affect the island of Rodrigues in a week, following Intense Tropical Cyclone Funani. Gelena brought strong winds that destroyed 90% of the electric grid on the island. Following the storm, the Mauritian government distributed Rs 35 million (US$1.02 million) to repair the damage.[29]

Intense Tropical Cyclone Haleh[edit]

Intense tropical cyclone (MFR)
Category 4 tropical cyclone (SSHWS)
Haleh 2019-03-04 0858Z.jpg Haleh 2019 track.png
DurationFebruary 28 – March 7
Peak intensity175 km/h (110 mph) (10-min)  945 hPa (mbar)

On February 28, Tropical Depression 10 formed in the south central Indian Ocean, south of the Maldives. On March 2, the system strengthened into Moderate Tropical Storm Haleh, before intensifying further into a severe tropical storm later that day. On March 3, Haleh intensified into a tropical cyclone. Finding itself in favourable conditions, Haleh continued to intensify and reached its peak intensity on March 4, as a Category 4-equivalent intense tropical cyclone, with 1-minute sustained winds of 215 km/h (130 mph). On March 5, Haleh meandered into hostile conditions with low sea surface ocean heat content and medium vertical wind shear, and the system weakened back to a Category 1 tropical cyclone. Haleh gradually weakened over the next couple of days, eventually degenerating into a post-tropical low late on March 7.

Intense Tropical Cyclone Idai[edit]

Intense tropical cyclone (MFR)
Category 3 tropical cyclone (SSHWS)
Idai 2019-03-14 1135Z.jpg Idai 2019 track.png
DurationMarch 4 – March 16
Peak intensity195 km/h (120 mph) (10-min)  940 hPa (mbar)

Tropical Depression 11 formed off the east coast of Mozambique on March 4. Afterward, the tropical depression drifted northeastward very slowly, making landfall on Mozambique later that day. On March 6, Tropical Depression 11 was given a yellow tropical cyclone development warning by the Joint Typhoon Warning Center (JTWC). On March 7, the storm turned west-southwestward, while continuing to retain its tropical identity overland. On March 8, Tropical Depression 11 weakened and turned back towards the east. Early on March 9, the tropical depression emerged into the Mozambique Channel and began to organize. On the same day, the JTWC stated that the system had a high probability for genesis into a tropical cyclone, and later on the same day, the system strengthened into a moderate tropical storm and received the name Idai. On March 10, Idai began to rapidly intensify, strengthening into a tropical cyclone near Madagascar, and the system made yet another turn westward, moving to the southwest. On the next day, the storm intensified into the seventh intense tropical cyclone of the season, and soon reached its peak intensity as a Category 3-equivalent tropical cyclone. On March 12, Idai began to weaken, as the system underwent an eyewall replacement cycle. On March 13, Idai began accelerating westward. At 00:00 UTC on March 15, the MFR reported that Idai had made landfall near Beira, Mozambique, with 10-minute sustained winds of 165 km/h (105 mph).[30] Idai quickly weakened after landfall, degenerating into a tropical depression later that day. Afterward, Idai slowly moved inland while dumping large amounts of rain, resulting in flash flooding.

As a tropical depression, Idai affected Malawi and Mozambique, during its first landfall. At least 56 people died, and 577 others were injured due to flooding in Malawi. About 83,000 people were displaced. The southern districts of Chikwawa and Nsanje became isolated by floodwaters.[31] In Mozambique, 66 people were killed by the flooding, and affected 141,000 people. The Council of Ministers required 1.1 billion metical (US$17.6 million) to help those who were affected by the flooding.[32]

Intense Tropical Cyclone Savannah[edit]

Intense tropical cyclone (MFR)
Category 2 tropical cyclone (SSHWS)
Savannah 2019-03-17 0724Z.jpg Savannah 2019 track.png
DurationMarch 17 (entered basin) – Present
Peak intensity165 km/h (105 mph) (10-min)  962 hPa (mbar)

On March 17, Severe Tropical Cyclone Savannah crossed over from the Australian region basin into the South-West Indian basin, shortly after reaching its peak intensity. Savannah was classified as an intense tropical cyclone on the South-West Indian Ocean scale after it entered the basin.

Storm names[edit]

Within the South-West Indian Ocean, tropical depressions and subtropical depressions that are judged to have 10-minute sustained windspeeds of 65 km/h (40 mph) by the Regional Specialized Meteorological Center on La Réunion Island, France (RSMC La Réunion) are usually assigned a name. However, it is the Sub-Regional Tropical Cyclone Advisory Centers in Mauritius and Madagascar who name the systems. The Sub-Regional Tropical Cyclone Advisory Center in Mauritius names a storm should it intensify into a moderate tropical storm between 55°E and 90°E. If instead a cyclone intensifies into a moderate tropical storm between 30°E and 55°E then the Sub-Regional Tropical Cyclone Advisory Center in Madagascar assigns the appropriate name to the storm. Beginning from the 2016–17 season, name lists within the South-West Indian Ocean will be rotated on a triennial basis. Storm names are only used once, so any storm name used this year will be removed from rotation and replaced with a new name for the 2021–22 season. The unused names are expected to be reused in the list for the 2021–22 season.[33]

  • Alcide
  • Bouchra
  • Cilida
  • Desmond
  • Eketsang
  • Funani
  • Gelena
  • Haleh
  • Idai
  • Joaninha (unused)
  • Kenneth (unused)
  • Lorna (unused)
  • Maipelo (unused)
  • Njazi (unused)
  • Oscar (unused)
  • Pamela (unused)
  • Quentin (unused)
  • Rajab (unused)
  • Savana (unused)
  • Themba (unused)
  • Uyapo (unused)
  • Viviane (unused)
  • Walter (unused)
  • Xangy (unused)
  • Yemurai (unused)
  • Zanele (unused)
  • Kenanga entered this basin as a moderate tropical storm from the Australian region on December 16, retaining its name assigned by TCWC Jakarta.
  • Savannah entered this basin as an intense tropical cyclone from the Australian region on March 17, retaining its name assigned by TCWC Perth.

Seasonal effects[edit]

This table lists all of the tropical cyclones and subtropical cyclones that were monitored during the 2018–2019 South-West Indian Ocean cyclone season. Information on their intensity, duration, name, areas affected, primarily comes from RSMC La Réunion. Death and damage reports come from either press reports or the relevant national disaster management agency while the damage totals are given in 2018 or 2019 USD.

Name Dates active Peak classification Sustained
wind speeds
Pressure Areas affected Damage
(USD)
Deaths Refs
01 September 13 – 17 Moderate tropical storm 75 km/h (45 mph) 1004 hPa (29.65 inHg) None None None
Alcide November 5 – 12 Intense tropical cyclone 165 km/h (105 mph) 965 hPa (28.50 inHg) Agaléga, Madagascar, Tanzania None None
Bouchra November 9 – 19 Severe tropical storm 95 km/h (60 mph) 990 hPa (29.23 inHg) None None None
Kenanga December 16 – 22 Intense tropical cyclone 185 km/h (115 mph) 942 hPa (27.81 inHg) None None None
Cilida December 16 – 24 Intense tropical cyclone 215 km/h (130 mph) 940 hPa (27.76 inHg) Mauritius None None
Desmond January 17 – 22 Moderate tropical storm 65 km/h (40 mph) 995 hPa (29.38 inHg) Mozambique, Madagascar Unknown None
Eketsang January 22 – 24 Moderate tropical storm 75 km/h (45 mph) 993 hPa (29.32 inHg) Madagascar Unknown 27
Funani February 3 – 10 Intense tropical cyclone 195 km/h (120 mph) 940 hPa (27.76 inHg) Rodrigues None None
Gelena February 4 – 14 Intense tropical cyclone 205 km/h (125 mph) 942 hPa (27.82 inHg) Madagascar, Mauritius, Rodrigues $1.02 million None
Haleh February 28 – March 7 Intense tropical cyclone 175 km/h (110 mph) 945 hPa (27.91 inHg) None None None
Idai March 4 – 16 Intense tropical cyclone 195 km/h (120 mph) 940 hPa (27.76 inHg) Mozambique, Malawi, Madagascar, Zimbabwe, South Africa $44 million 314
Savannah March 17 – Present Intense tropical cyclone 165 km/h (105 mph) 962 hPa (28.41 inHg) None None None
Season aggregates
12 systems September 13 – Present 215 km/h (130 mph) 940 hPa (27.76 inHg) $45 million 341


See also[edit]

References[edit]

  1. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201809140600_1_1_20182019.pdf (in French)
  2. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201809150600_3_1_20182019.pdf (in French)
  3. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201809170600_7_1_20182019.pdf (in French)
  4. ^ "Saisons cycloniques archivées: Tempête Tropicale Modérée 01" (in French). Météo-France. 2018. Retrieved November 8, 2018.
  5. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811060600_1_2_20182019.pdf (in French)
  6. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811061800_ALCIDE.pdf (in French)
  7. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811070600_ALCIDE.pdf (in French)
  8. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811080600_ALCIDE.pdf (in French)
  9. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811081200_ALCIDE.pdf (in French)
  10. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811091200_ALCIDE.pdf (in French)
  11. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811110000_EX-ALCIDE.pdf (in French)
  12. ^ http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/cmrs/CMRSF_201811111200_EX-ALCIDE.pdf (in French)
  13. ^ "12 UTC Gradient Level Wind Analysis Chart". Bureau of Meteorology. 1 November 2018.
  14. ^ "Tropical Activity Bulletin" (PDF). Météo-France La Réunion. 9 November 2018.
  15. ^ "Moderate Tropical Storm Bouchra Forecast Track Map". Météo-France La Réunion. 10 November 2018. Archived from the original on 11 November 2018.
  16. ^ "Current Tropical Cyclone Basin Activity". Meteorology, Climatology and Geophysical Agency. 10 November 2018. Archived from the original on 10 November 2018.
  17. ^ "Tropical Cyclone 04S Warning #1". Joint Typhoon Warning Center. 10 November 2018. Archived from the original on 10 November 2018.
  18. ^ "Tropical Activity Bulletin" (PDF). Météo-France La Réunion. 10 November 2018.
  19. ^ "Bouchra Analysis Bulletin #2" (PDF). Météo-France La Réunion. 11 November 2018.
  20. ^ a b "Tropical Storm Bouchra Advisory (12 UTC)" (PDF). Météo-France La Réunion. 11 November 2018. Retrieved 14 November 2018.
  21. ^ a b "Tropical Activity Bulletin" (PDF). Météo-France La Réunion. 13 November 2018. Retrieved 13 November 2018.
  22. ^ "Western Region Tropical Cyclone Outlook". Bureau of Meteorology. 13 November 2018. Archived from the original on 13 November 2018. Retrieved 13 November 2018.
  23. ^ "Western Region Tropical Cyclone Outlook". Bureau of Meteorology. 14 November 2018. Archived from the original on 14 November 2018. Retrieved 14 November 2018.
  24. ^ "Cilida: un petit tour puis s'en va". Le Express. December 23, 2018. Retrieved January 3, 2019.
  25. ^ Shabneeze Oozeear (December 25, 2018). "Cilida : les pluies apportées par le cyclone bénéfique aux plantations". Mauritius Broadcasting Corporation. Retrieved January 3, 2019.
  26. ^ Hélia Chopo (January 23, 2019). "Mais de 400 famílias afectadas pela tempestade "Desmond" em Sofala" (in Portuguese). O PAÍS. Retrieved January 30, 2019.
  27. ^ "Madagascar : 27 morts suite au fortes pluies et à la Tempête EKETSANG" (in French). Cyclone Ocean Indien. January 31, 2019. Retrieved February 3, 2019.
  28. ^ "Cyclone Funani : Air Mauritius annule six vols de Rodrigues" (in French). Le Mauricien. February 7, 2019. Retrieved February 11, 2019.
  29. ^ "Mauritian government set to disburse funds to cylone-affected community". Africa Daily Voice. February 11, 2019. Retrieved February 12, 2019.
  30. ^ "Intense Tropical Cyclone Idai Warning 26" (PDF). Meteo France La Reunion. 15 March 2019. Archived from the original (PDF) on 15 March 2019. Retrieved 15 March 2019.
  31. ^ Phiri, Frank (March 13, 2019). "Malawi flooding death toll rises to 56, braced for Cyclone Idai". Reuters. Retrieved March 13, 2019.
  32. ^ "Floods kill 66 in Mozambique". Gulf Times. March 13, 2019. Retrieved March 13, 2019.
  33. ^ Regional Association I Tropical Cyclone Committee (2016). "Tropical Cyclone Operational Plan for the South-West Indian Ocean" (PDF). World Meteorological Organization. Retrieved 2016-10-05.

External links[edit]