Misplaced Pages

Revision as of 20:25, 6 March 2021

2020–21 South-West Indian Ocean cyclone season
Season summary map
Seasonal boundaries
First system formed	12 November 2020
Last system dissipated	Season ongoing
Strongest storm
Name	Faraji
• Maximum winds	230 km/h (145 mph) (10-minute sustained)
• Lowest pressure	925 hPa (mbar)
Seasonal statistics
Total disturbances	14
Total depressions	14
Total storms	10
Tropical cyclones	6
Intense tropical cyclones	3
Very intense tropical cyclones	1
Total fatalities	34 total
Total damage	$10 million (2021 USD)
Related articles
2020–21 Australian region cyclone season 2020–21 South Pacific cyclone season
South-West Indian Ocean tropical cyclone seasons 2018–19, 2019–20, 2020–21, 2021–22, 2022–23

The 2020–21 South-West Indian Ocean cyclone season is an ongoing period of tropical cyclogenesis. The season started with the formation of Cyclone Alicia in the extreme northeast section of the basin on 12 November, just before the official start of the season, which marked the third season in a row in which a tropical cyclone formed before the official beginning of the season. It officially began on 15 November 2020, and will officially end on 30 April 2021, with the exception for Mauritius and the Seychelles, for which it will officially end on 15 May 2021. 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 and unofficially by the Joint Typhoon Warning Center.

Seasonal forecasts

/>

Pre-season forecast

On November 16, 2020, the Météo France issued a forecast for the 2020-21 season, predicting activity that is near to above normal. In this report, the organization predicts 9-12 named storms and 5-7 tropical cyclones.

|Track=Marian 2021 track.png |Formed=1 March (Entered basin) |Dissipated=
2 March (Exited basin) |10-min winds=90 |1-min winds=90 |Pressure=950 }} At 06:00 UTC on 1 March, Severe Tropical Cyclone Marian entered the area of responsibility of Météo-France La Réunion (MFR) after crossing the 90th meridian east from the Australian region. At the time, the system was assessed as a Category 3 severe tropical cyclone on the Australian scale, with maximum 10-minute sustained winds of 150 km/h (90 mph) and a central atmospheric pressure of 964 hPa (28.47 inHg). Upon entering the South-West Indian Ocean (SWIO) basin, the system was classified as a tropical cyclone by MFR. Due to the short period of time that Marian was expected to stay in the SWIO basin before returning to the Australian region, it was agreed that the MFR would defer responsibility for providing official information on the system to the Australian Bureau of Meteorology (BOM). Upon entering the basin, Marian become slow-moving in a competing steering environment, caught between ridges of high pressure to the north and south. After a plateau in intensity lasting for more than a day, marked by an eyewall replacement cycle and periodic waxing and waning of deep convection around the core, Marian began to strengthen again on 2 March. Maximum 10-minute sustained winds increased to 165 km/h, with gusts to 230 km/h and a minimum atmospheric pressure of 950 hPa (28.05 inHg), and the system was upgraded by the BOM to Category 4 on the Australian scale, equivalent to an intense tropical cyclone in the SWIO basin. The increase in intensity proved short-lived, however, and the cyclone began to gradually weaken as it commenced a slow track back towards the east. Marian exited the SWIO basin just before 12:00 UTC on 2 March.

Intense Tropical Cyclone Habana

Intense Tropical Cyclone Habana
Current storm status Intense tropical cyclone (MFR)
Current storm status Category 4 tropical cyclone (1-min mean)
Satellite image Forecast map
As of:	12:00 UTC, 6 March
Location:	16°18′N 78°18′E / 16.3°N 78.3°E / 16.3; 78.3 (Intense Tropical Cyclone Habana)
Sustained winds:	110 knots (205 km/h; 125 mph) (10-min mean) 120 knots (220 km/h; 140 mph) (1-min mean) gusting to 155 knots (285 km/h; 180 mph)
Pressure:	940 hPa (27.76 inHg)
Movement:	ESE at 4 km/h (0 kn; 0 mph)
See latest official information.

On 2 March, Météo-France La Réunion (MFR) began to monitor a disturbance associated with the convergence of the easterly monsoon flow and the trade winds. This was soon followed by the JTWC issuing a TCFA on the disturbance, which had previously been designated as Invest 90S, early the next day. Early by the next day, the system was designated as a zone of disturbed weather. As the system slowly developed a discernible core, it was designated Moderate Tropical Storm Habana at 12:00 UTC 4 March. Around the same time, the JTWC designated the system as a tropical storm. Under the influence of a near equatorial ridge, Habana was slowly steered east-southeastward and continued steady strengthening. Habana reached severe tropical storm strength on 5 March, with a shallow eye forming. Forecasts at the time showed a weakening system, but Habana underwent extreme rapid intensification in exponentially better conditions from a 95 km/h (60 mph) severe tropical storm to an intense tropical cyclone with winds of 185 km/h (115 mph) in 12 hours that same day.. The storm slowed down in strengthening but maintained a very well defined pinhole eye and compact core structure while the JTWC assessed Habana with 1-minute sustained winds of 230 km/h (145 mph) at the time, equivalent to a mid-strength Category 4 hurricane.

Current storm information

As of 12:00 UTC on 6 March, Intense Tropical Cyclone Habana is located within 20 nautical miles of 16°18′S 78°18′E / 16.3°S 78.3°E / -16.3; 78.3 (Habana). It is currently moving east-south-east with the speed of 4 km/h (0 kn; 0 mph). Maximum 10-minute sustained winds are at 110 knots (205 km/h; 125 mph) while maximum 1-minute sustained winds are at 120 knots (220 km/h; 140 mph), with gusts up to 155 knots (285 km/h; 180 mph). The minimum central barometric pressure is 940 hPa (27.76 inHg).

For the latest official information see:

• MFR's Cyclonic Analysis and Forecast Bulletins on Intense Tropical Cyclone 13 (Habana)
• JTWC's Tropical Cyclone Warning on Tropical Cyclone 24S (Habana)

Tropical Depression 14

Tropical depression (MFR)
Duration	3 March – Present
Peak intensity	55 km/h (35 mph) (10-min); 996 hPa (mbar)

On 3 March, a weak tropical disturbance quickly formed within the monsoonal flow in the Mozambique Channel. The weak system slowly became more organized despite moderate wind shear, strengthening to a tropical depression by the next day. Before the system could strengthen in relatively favorable conditions, it made landfall in Madagascar around 09:50 UTC 5 March as a tropical depression and began to rapidly weaken. After accelerating through the Malagasy landmass, the system re-emerged over water near Vatomandry on 6 March, the circulation of the storm having become elongated.

On 6 March, Réunion was put under a yellow alert due to the depression. Officials anticipated a brief but intense period of severe weather related to the cyclone.

Storm names

Tropical depressions and subtropical depressions are assigned a name when they intensify to have 10-minute sustained winds of 65 km/h (40 mph) as assessed by the Regional Specialized Meteorological Center on La Réunion Island, France (RSMC La Réunion). The Sub-Regional Tropical Cyclone Advisory Center in Mauritius assigns a name to a cyclone if it intensifies into a moderate tropical storm between 55°E and 90°E. A cyclone is assigned a name by the Sub-Regional Tropical Cyclone Advisory Center in Madagascar if it intensifies into a moderate tropical storm between 30°E and 55°E. From the 2016–17 season, name lists within the South-West Indian Ocean are rotated on a triennial basis. Storm names that are assigned during the season are used once. Therefore, all storm names used this year will be removed from rotation and replaced with a new name for the 2023–24 season, while the unused names will remain on the list. The names used during the 2017–18 season were Ava, Berguitta, Cebile, Dumazile, Eliakim, and Fakir. This year they were replaced by Alicia, Bongoyo, Chalane, Danilo, Eloise, and Faraji.

Others

If a tropical cyclone enters the South-West Indian basin from the Australian region basin (west of 90°E), it will retain the name assigned to it by the Australian Bureau of Meteorology (BOM). The following storms were named in this manner:

• Joshua
• Marian

Season effects

This table lists all of the tropical cyclones and subtropical cyclones that were monitored during the 2020–2021 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 2020 or 2021 USD.

See also

• List of Southern Hemisphere tropical cyclone seasons
• Tropical cyclones in 2020 and 2021
• Atlantic hurricane seasons: 2020, 2021
• Pacific hurricane seasons: 2020, 2021
• Pacific typhoon seasons: 2020, 2021
• North Indian Ocean cyclone seasons: 2020, 2021
• 2020–21 Australian region cyclone season
• 2020–21 South Pacific cyclone season

References

1. "Background Information: The Southwest Indian Ocean". Climate Prediction Center. National Oceanic and Atmospheric Administration. 9 August 2012. Archived from the original on 22 September 2012. Retrieved 13 December 2019.
2. Cite error: The named reference HURDAT was invoked but never defined (see the help page).
3. Saunders, Marc; Lea, Adam (9 December 2020). "Extended Range Forecast for Atlantic Hurricane Activity in 2021" (PDF). TropicalStormRisk.com.
4. ^ "Cyclone Marian Technical Bulletin (06Z)". Australian Bureau of Meteorology. 1 March 2021. Archived from the original on 1 March 2021. Retrieved 1 March 2021.
5. ^ "Tropical Cyclone Activity Bulletin for the South-West Indian Ocean (12Z)" (PDF). Météo-France La Réunion (in French). 28 February 2021. Retrieved 1 March 2021.{{cite web}}: CS1 maint: url-status (link)
6. "Cyclone Marian Forecast Track Map (06Z)". Australian Bureau of Meteorology. 1 March 2021. Archived from the original on 1 March 2021. Retrieved 1 March 2021.
7. "Tropical Cyclone 22S (Marian) Warning #8 (12Z)". Joint Typhoon Warning Center. Naval Meteorology and Oceanography Command. 1 March 2021. Archived from the original on 1 March 2021. Retrieved 1 March 2021.
8. "Cyclone Marian Technical Bulletin (12Z)". Australian Bureau of Meteorology. 28 February 2021. Archived from the original on 28 February 2021. Retrieved 28 February 2021.
9. "Tropical Cyclone 22S (Marian) Warning #7 (00Z)". Joint Typhoon Warning Center. Naval Meteorology and Oceanography Command. 1 March 2021. Archived from the original on 1 March 2021. Retrieved 1 March 2021.
10. ^ "Cyclone Marian Forecast Track Map (00Z)". Australian Bureau of Meteorology. 2 March 2021. Archived from the original on 2 March 2021. Retrieved 2 March 2021.
11. "Cyclone Marian Technical Bulletin (00Z)". Australian Bureau of Meteorology. 2 March 2021. Archived from the original on 2 March 2021. Retrieved 2 March 2021.
12. "Cyclone Marian Technical Bulletin (12Z)". Australian Bureau of Meteorology. 2 March 2021. Archived from the original on 2 March 2021. Retrieved 2 March 2021.
13. "Cyclone Marian Forecast Track Map (12Z)". Australian Bureau of Meteorology. 2 March 2021. Archived from the original on 2 March 2021. Retrieved 2 March 2021.
14. "Tropical Cyclone Activity Bulletin for the South-West Indian Ocean (12Z)" (PDF). Météo-France La Réunion (in French). 2 March 2021. Retrieved 2 March 2021.{{cite web}}: CS1 maint: url-status (link)
15. "Bulletin for Cyclonic Activity And Significant Tropical Weather in the Southwest Indian Ocean 2021/03/02 AT 1200 UTC" (PDF). Meteo France La Reunion. 2 March 2021.{{cite web}}: CS1 maint: url-status (link)
16. "TROPICAL CYCLONE FORMATION ALERT (INVEST 90S)". Joint Typhoon Warning Center. 4 March 2021. Retrieved 4 March 2021.
17. "A Zone of Disturbed Weather 13 Warning Number 1/13/20202021" (PDF). Meteo France La Reunion. 3 March 2021.{{cite web}}: CS1 maint: url-status (link)
18. "A Moderate Tropical Storm 13 (Habana) Warning Number 4/14/20202021" (PDF). Meteo France La Reunion. 4 March 2021.{{cite web}}: CS1 maint: url-status (link)
19. "Tropical Cyclone 24S (Habana) Warning #05". Joint Typhoon Warning Center. Archived from the original on 6 March 2021.
20. "Moderate Tropical Storm 13 (Habana) Warning Number 5/13/20202021" (PDF). Meteo France La Reunion. 4 March 2021.{{cite web}}: CS1 maint: url-status (link)
21. "Severe Tropical Storm 13 (Habana) Warning Number 6/13/20202021" (PDF). Meteo France La Reunion. 5 March 2021.{{cite web}}: CS1 maint: url-status (link)
22. "Intense Tropical Cyclone 13 (Habana) Warning Number 8/13/20202021". Meteo France La Reunion. 5 March 2021.{{cite web}}: CS1 maint: url-status (link)
23. "Tropical Cyclone 24S (Habana) Warning #05". Joint Typhoon Warning Center. 6 March 2021. Archived from the original on 6 March 2021.
24. "A Tropical Disturbance 14 Warning Number 1/14/202021" (PDF). Meteo France La Reunion. 4 March 2021.{{cite web}}: CS1 maint: url-status (link)
25. "A Tropical Depression 14 Warning Number 3/14/20202021" (PDF). Meteo France La Reunion. 5 March 2021.{{cite web}}: CS1 maint: url-status (link)
26. "A Tropical Depression 14 Warning Number 5/14/20202021" (PDF). Meteo France La Reunion. 5 March 2021.{{cite web}}: CS1 maint: url-status (link)
27. "Zone of Disturbed Weather 14 Warning Number 8/14/20202021". Meteo France La Reunion. 6 March 2021.{{cite web}}: CS1 maint: url-status (link)
28. "The tropical depression as close as possible to Reunion Island on Saturday night in". Retrieved 6 March 2021.
29. "La future tempête Iman est ressortie en mer et va se rapprocher des Mascareignes". www.cycloneoi.com (in French). Retrieved 6 March 2021.
30. "System Names for the Current Season". Meteo France La Reunion. Retrieved 15 November 2020.
31. Regional Association I Tropical Cyclone Committee (2016). "Tropical Cyclone Operational Plan for the South-West Indian Ocean" (PDF). World Meteorological Organization. Retrieved 5 October 2016.
32. "Death toll from storm Chalane in Mozambique rises to 7 | Nation". nation.africa. Retrieved 3 January 2021.
33. "Southern Africa – Tropical Cyclone Eloise Flash Update No.5, As of 22 January 2021". ReliefWeb. 22 January 2021. Retrieved 22 January 2021.
34. "Global Catastrophe Recap 2021" (PDF). AON Benfield. Retrieved 14 February 2021.

External links

• Météo-France La Réunion
• Direction Générale de la Météorologie de Madagascar
• Mauritius Meteorological Services
• Joint Typhoon Warning Center (JTWC)

v t e Tropical cyclones of the 2020–21 South-West Indian Ocean cyclone season
	TCAlicia TD02 STSBongoyo STSChalane TD05 STSDanilo TCEloise STSJoshua TD09 VITCFaraji TCGuambe TCMarian VITCHabana MTSIman TD15 TCJobo
Category

• Current events
• 2020–21 South-West Indian Ocean cyclone season
• Tropical cyclones in 2020
• Tropical cyclones in 2021