Meteorological history | |
---|---|
Formed | March 27,2014 |
Remnant low | April 1,2014 |
Dissipated | April 5,2014 |
Very intense tropical cyclone | |
10-minute sustained (MF) | |
Highest winds | 230 km/h (145 mph) |
Highest gusts | 325 km/h (200 mph) |
Lowest pressure | 915 hPa (mbar);27.02 inHg |
Category 4-equivalent tropical cyclone | |
1-minute sustained (SSHWS/JTWC) | |
Highest winds | 240 km/h (150 mph) |
Lowest pressure | 926 hPa (mbar);27.34 inHg |
Overall effects | |
Fatalities | 8 |
Missing | 9 |
Damage | Unknown |
Areas affected | Mozambique,Comoro Islands,Madagascar |
IBTrACS / [1] | |
Part of the 2013–14 South-West Indian Ocean cyclone season |
Very Intense Tropical Cyclone Hellen of March 2014 was one of the most powerful tropical cyclones in the Mozambique Channel on record,as well as the most intense of the 2013–14 South-West Indian Ocean cyclone season. Hellen formed on March 26 in the northern portion of the channel,and the storm brought rainfall to coastal Mozambique while in its formative stages. While moving southeastward,it developed an organized area of convection over the center of circulation. Warm waters allowed Hellen to rapidly intensify while passing south of the Comoros,with a well-defined eye forming in the middle of the thunderstorms. The cyclone attained peak intensity March 30,with maximum sustained winds estimated 230 km/h (145 mph) according to the Regional Specialized Meteorological Center,Météo-France in La Réunion. Subsequently,Hellen weakened quickly due to dry air and land interaction with Madagascar,and the storm's eye dissipated. On March 31,the storm made landfall in northwestern Madagascar as a weakened cyclone,despite previous forecasts for the center to remain over water. By April 1,Hellen was no longer a tropical cyclone after most of the convection dissipated. The remnants turned to the west,moving over Mozambique without redeveloping,later dissipating on April 5.
Early in its existence,Hellen's rainfall in Mozambique destroyed hundreds of houses and a bridge. Flooding killed four people in the country,three of whom due to a home collapsing. Later,the cyclone passed south of the Comoros islands,causing flooding due to high storm surge and waves that killed one person. The storm forced 8,956 people to evacuate their homes due to the threat for landslides,while 901 houses were damaged or destroyed. On nearby Mayotte,high rainfall flooded rivers,sweeping one car away. In northwestern Madagascar,Hellen damaged or destroyed 611 houses,leaving 1,736 people homeless. The storm killed three people after capsizing a boat.
On March 25, 2014, a weak area of low pressure accompanied by broad, flaring convection became increasingly organized over Mozambique. Owing to favorable environmental conditions, featuring low wind shear, vorticity became more enhanced and symmetrical. [2] A compact system, the low steadily organized as it emerged over the Mozambique Channel on March 26. Though continued land interaction initially hindered development, [3] enhanced outflow supported convective development as it straddled the Mozambique–Tanzania border. With high sea surface temperatures in the storm's track, the JTWC anticipated further organization and issued a Tropical Cyclone Formation Alert at 2000 UTC on March 26. [4] Once further offshore on March 27, the Regional Specialized Meteorological Center Météo-France in La Réunion classified the system as Disturbance 14. [5] Drifting slowly eastward, a prominent feeder band developed along the system's eastern side; however, this band disrupted low-level inflow of warm, moist air, and suppressed convection over the circulation center. [6]
Though convection later began to consolidate into a small central dense overcast (CDO) feature by March 28, continued disruption of the low-level inflow prevented much development. Météo-France noted that despite forecasting the storm to peak as a moderate tropical storm, with winds of 85 km/h (50 mph), there was potential for rapid intensification due to the storm's small size. [7] Conversely, the JTWC noted that proximity to land and dry mid-level air, represented by surface outflow boundaries, could hamper significant development. Once further over the Mozambique Channel, the system became increasingly organized and the JTWC initiated advisories on the storm as Tropical Cyclone 21S. [8] Météo-France followed suit at 0000 UTC on March 29 and classified the cyclone as a moderate tropical storm, with the tropical cyclone warning center in Madagascar assigning the name Hellen. [9] Hellen soon assumed an east-southeast track toward Madagascar, as a ridge established itself to the northeast. Throughout March 29, the storm became increasingly organized with an eye apparent on microwave satellite imagery. [10]
Rapid to explosive intensification ensued during the later half of March 29 into March 30 at a rate Météo-France later referred to as "astounding". [11] Deep convective banding wrapped around a ragged eye, [12] which soon contracted to "pinhole" size. [13] This prompted Météo-France to upgrade Hellen to a tropical cyclone with winds estimated at 155 km/h (100 mph) at 0000 UTC on March 30. [1] Six hours later, they further upgraded the storm to an intense tropical cyclone with winds of 195 km/h (120 mph). [11] Hellen attained its peak intensity between 1100 and 1500 UTC as a very intense tropical cyclone, with winds of 230 km/h (145 mph), gusts reaching 325 km/h (200 mph), and a barometric pressure of 915 mbar (hPa; 27.02 inHg). [1] This ranked it as one of the most powerful storms over the Mozambique Channel on record. [14] The storm featured a 20 km (12 mi) wide eye embedded within a symmetrical and intense CDO, spanning 240 km (150 mi) across. [15] The JTWC estimated Hellen to have attained one-minute sustained winds of 250 km/h (155 mph), making it a high-end Category 4-equivalent cyclone on the Saffir–Simpson hurricane wind scale, although this was lowered to 240 km/h (150 mph) in reanalysis. [16]
After peak intensity, the cyclone's eye soon began to fill and cool as weakening ensued. Defying previous forecasts, Hellen continued on a southeasterly track toward Madagascar and the likelihood of it making landfall became apparent. [14] By the end of March 30, Hellen's eye had collapsed and disappeared from satellite imagery, [17] as the combination of dry air and land interaction took their toll on the storm. [18] At about 0800 UTC on March 31, Hellen made landfall on Mitsinjo with winds of 110 km/h (70 mph), and the previously unfavorable conditions coupled with land interaction to induce rapid weakening. [19] The ridge to the east turned Hellen to a southwest drift over land. By early on April 1, the convection largely dissipated as the center became difficult to locate, with peak winds dropping to 45 km/h (30 mph). As a result, Météo-France discontinued advisories that day, [20] as did the JTWC. [21] The remnants moved back over open waters, but were not expected to reorganize due to the poor nature of the convection. [22] As the low continued to the west, the convection increased on April 4 while approaching the coastline of Mozambique, [23] although the system failed to redevelop before moving onshore. [24]
During its formative stages, Hellen meandered around northern Mozambique and produced prolonged heavy rains over the region. The city of Pemba in Cabo Delgado Province was the hardest hit area, with the Messalo River over-topping its banks. Tagir Carimo, mayor of Pemba, described the rains as the heaviest he had seen in 20 years. More than 100 poorly constructed homes collapsed in the floods while severe erosion exposed and destroyed water pipes. A major bridge connecting Pemba to surrounding areas was washed away by the Messalo river. [25] This isolated the northern portion of Cabo Delgado Province from the rest of the country, forcing ferries to transport cars. [26] Three people died in the district of Cariaco when their home collapsed while a fourth drowned in Chiuba. [25] Distributing assistance following the storm was disrupted by damaged roads. [27]
Heavy rains and storm surge caused significant damage on all three islands of the Comoros, with the worst occurring on Anjouan. [28] There, 901 houses were damaged, of which about 20% were destroyed. [29] Flooding displaced 389 people in Salamani where 33 mud-built homes were destroyed. Landslides isolated the villages of Chiconi, Hamaba, Koni-Djodjo, Miringoni, and Nioumachioi, [28] and damaged a road between Ngandzalé and Domoni. On the island, 7,879 people had to evacuate their houses due to the risk of further landslides, [29] some of whom went to schools set up as shelters while others stayed with family or friends. [30] Storm surge on Mohéli flooded parts of Tsamia, Walla, and Zirindani, resulting in one fatality. [28] Several houses were damaged on the island, and Djandro lost power due to a damaged power line. The Prince Said Ibrahim International Airport in Moroni on Grande Comore was closed for about 24 hours due to the storm. Also on the island, a road was damaged, and one house was flooded. [29] Shortly after the storm, workers began repairing roads and distributing aid. [30]
Though the center of Cyclone Hellen remained south of Mayotte, it prompted an "orange alert" on March 30 for the area due to the potential for hurricane-force gusts. [31] The storm's rapid intensification caught most residents on the island off-guard, with widespread disruptions to traffic and electricity taking place. Wind gusts up to 100 km/h (62 mph) downed trees and power lines, blocking off roads while heavy rains caused significant flooding. [32] A peak 24‑hour rainfall of 239 mm (9.4 in) was measured in Mtsamboro between March 29 and 30. [33] In M'Tsangamouji, cars were swept away by a swollen river. Along the coast, waves up to 5 m (16 ft) damaged marinas in Dzaoudzi, Hagnoundrou, and Mamoudzou where skiffs were smashed against rocks or stranded. [32]
On March 31, a boat capsized off the coast of northwest Madagascar, killing three and leaving nine others missing. [28] High seas washed away 20 canoes along the coast. [34] Initial assessments of damage across Madagascar were initially hampered by poor weather and inaccessibility. [28] The storm flooded 7,795 ha (19,260 acres) of rice fields across the country, as well as 114 ha (280 acres) of other crops, [34] threatening harvests after a locust outbreak had occurred in the months prior to the storm. [30] The storm also killed 23 zebu and damaged two dams. Cyclone Hellen destroyed 437 houses and damaged or flooded 174 others, leaving 1,736 people homeless during its passage. The storm also damaged two health facilities and five schools. [34] Overall impact from Hellen was less than expected due to its weakening, with most telephone lines still intact. [27]
Due to the storm affecting water access in northwestern Madagascar, there was concern for a disease outbreak, with a flu outbreak noted in Mahajanga. The national Red Cross utilized 54 volunteers to assist in the storm's aftermath, such as distributing kitchen kits and agriculture units. Residents donated 2 million ariary ($800 USD) to the Red Cross, which were used to purchase medicines, while the government provided 600 kg (1,300 lb) of rice for affected residents. [35]
Intense Tropical Cyclone Jokwe was the first tropical cyclone to make landfall in Mozambique since Cyclone Favio struck in the previous year, and was the most recent cyclone to make landfall on Mozambique until Cyclone Dineo in 2017. The tenth named storm of the 2007–08 South-West Indian Ocean cyclone season, Jokwe was first classified as a tropical depression on 2 March over the open Southwest Indian Ocean. It tracked west-southwest, crossing northern Madagascar as a tropical storm on 5 March before intensifying into a tropical cyclone on 6 March. Jokwe rapidly intensified to reach peak winds of 195 km/h (121 mph), before weakening slightly and striking Nampula Province in northeastern Mozambique. It quickly weakened while paralleling the coastline, though the storm restrengthened as it turned southward in the Mozambique Channel. Late in its duration, it remained nearly stationary for several days, and steadily weakened due to wind shear before dissipating on 16 March.
The 2010–11 South-West Indian Ocean cyclone season was the least active cyclone season on record in the basin, tied with 1982–83, producing only three systems of gale intensity. This was due to cooler than normal water temperatures and the Walker circulation – a broad atmospheric circulation – causing unusually moist conditions in the eastern Indian Ocean and unusually dry conditions in the western Indian Ocean. The basin includes the waters of the ocean south of the equator and west of 90º E to the eastern coast of Africa.
Severe Tropical Storm Cyprien was a short-lived tropical cyclone that caused minor damage in Madagascar. Forming on December 30, 2001, Cyprien quickly strengthened in a slightly favorable environment. By January 2, the storm attained its peak intensity with winds of 100 km/h (65 mph) according to Météo-France and 95 km/h (60 mph) according to the Joint Typhoon Warning Center. Later that day the storm made landfall in Morombe, at a weaker intensity, and dissipated early on January 3. Throughout the affected areas, Cyprien destroyed 957 structures, leaving 1.16 billion Malagasy franc in damages. No fatalities were reported; however two people were listed as missing.
Tropical Cyclone Bingiza was the only named storm to make landfall in the inactive 2010–11 South-West Indian Ocean cyclone season. The second of three storms, Bingiza developed on 9 February to the northeast of Madagascar. For a few days it meandered generally southwestward, failing to intensify significantly. On 12 February, the storm began a steady westward track as environmental conditions became more favorable. In a 24‑hour period, Bingiza developed from a moderate tropical storm into an intense tropical cyclone with a well-defined eye. After attaining peak 10–minute sustained winds of 155 km/h (96 mph), the cyclone moved ashore in northeastern Madagascar on 14 February and quickly weakened as it crossed the country. Bingiza emerged into the Mozambique Channel as a weak tropical disturbance, and it turned southward to move across western Madagascar. Bingiza attained tropical storm status before making its final landfall near Morondava, degenerating into a remnant low on 17 February, and completely dissipating two days later.
The 2012–13 South-West Indian Ocean cyclone season was a slightly above average event in tropical cyclone formation in the Southern hemisphere tropical cyclone year starting on July 1, 2012, and ending on June 30, 2013. Within this basin, tropical and subtropical disturbances are officially monitored by the Regional Specialised Meteorological Centre on Réunion island, while the Mauritius and Madagascar weather services assign names to significant tropical and subtropical disturbances. The first tropical disturbance of the season developed on October 12 and rapidly developed into the earliest known intense tropical cyclone on record during October 14.
The 2013–14 South-West Indian Ocean cyclone season was an above-average event in tropical cyclone formation. The season officially began on July 1, 2013, though the first tropical system designated by Météo-France was a short-lived tropical disturbance that developed on July 8. However, the first named storm was Cyclone Amara in December. Bruce was the first very intense tropical cyclone since Edzani in 2010, which originated from the Australian region. The strongest system of the cyclone season was Hellen, also one of the most intense tropical cyclones over the Mozambique Channel. The season officially ended on June 30, 2014
The 2014–15 South-West Indian Ocean cyclone season was an above average event in tropical cyclone formation. It began on November 15, 2014, and ended on April 30, 2015, with the exception for Mauritius and the Seychelles, for which it ended on May 15, 2015. 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.
Intense Tropical Cyclone Favio was the first known tropical cyclone that passed south of Madagascar to strike Africa as an intense tropical cyclone. Early on 11 February 2007, a zone of disturbed weather formed east of Madagascar. Four days later, Favio was named as intensified to a moderate tropical storm while moving southwest. On 18 February, the storm was upgraded into a severe tropical storm. Then, it turned west in the general direction of Mozambique. Continuing to intensify, Favio was upgraded to a tropical cyclone early on 19 February. Subsequently, the storm began to undergo rapid deepening; the small storm reached intense tropical cyclone status the next day before peaking in intensity. However, the cyclone had weakened somewhat prior to making landfall on 22 February in the Inhambane Province in Mozambique. It rapidly weakened over land and dissipated the next day.
Very Intense Tropical Cyclone Hudah was a powerful and destructive tropical cyclone that affected Southeast Africa in April 2000. It was the last in a series of three cyclones that impacted Madagascar during the year. Hudah first developed as a disturbance embedded within the monsoon trough on 22 March, within the Australian region cyclone basin. Moving westward as the result of a strong subtropical ridge to its south, the storm quickly intensified, and reached Category 2 cyclone intensity on 25 March before entering the Southwest Indian cyclone basin. For various reasons that remain unknown, the cyclone was only designated a name by the time it had crossed into the area of responsibility of the Regional Specialized Meteorological Center in Réunion. Nonetheless, Météo-France (MFR) assigned the name Hudah to the cyclone. An eye formed, and the storm intensified into a tropical cyclone on 27 March well to the southeast of Diego Garcia. On 1 April, the MFR upgraded it to a very intense tropical cyclone, estimating peak 10-minute winds of 225 km/h (140 mph). By contrast, the Joint Typhoon Warning Center (JTWC) estimated 1-minute winds of 235 km/h (146 mph). At this time, the MFR estimated the pressure to have been 905 hPa (mbar), making Hudah the most intense tropical cyclone worldwide in 2000. Cyclone Hudah maintained peak winds until making landfall just southeast of Antalaha, Madagascar on 2 April. It weakened greatly over land, but re-attained tropical cyclone status on 5 April after moving over the Mozambique Channel. Hudah reached 10-minute winds of 160 km/h (99 mph) by the time it made landfall on Mozambique near Pebane, Mozambique, on 8 April, and dissipated by the next day.
Intense Tropical Cyclone Bejisa was a powerful tropical cyclone that affected the islands of Réunion and Mauritius in early January 2014. In late December 2013, a tropical disturbance developed to the north of Madagascar. With favorable conditions, the low developed into a disturbance and soon into a depression on 28 December. The system continued to develop and intensified into Moderate Tropical Storm Bejisa on 29 December, with rapid intensification occurring. It developed into an Intense Tropical Cyclone on 30 December, reaching peak maximum sustained winds of 165 km/h (103 mph). Due to an eyewall replacement cycle, Bejisa weakened, but re-intensified to a secondary peak of 160 km/h (99 mph) on 1 January. Increased wind shear weakened the eyewall, which passed within 15 km (9.3 mi) of Réunion. After having moved generally south-southeastward for much of its duration, Bejisa turned to the southwest on 3 January, by which time it had weakened to tropical storm status. It became a post-tropical cyclone on 5 January after the convection weakened over the center, and Bejisa became extratropical the next day as it meandered southwest of Madagascar.
The 2015–16 South-West Indian Ocean cyclone season was a slightly below average event in tropical cyclone formation. The annual cyclone season began on November 15, 2015, with the first storm, Annabelle, forming four days following. The final and strongest storm, Fantala, dissipated on April 23, 2016, a week before the season ended on April 30 for most of the region. In Mauritius and the Seychelles, the cyclone season ended half a month later, on May 15. The season's activity was influenced by an ongoing El Niño, and a positive Indian Ocean Dipole.
Very Intense Tropical Cyclone Fantala was the most intense tropical cyclone recorded in the South-West Indian Ocean in terms of sustained winds. Part of the 2015–16 cyclone season, Fantala formed on 11 April to the south of Diego Garcia, an island in the central Indian Ocean. With a ridge to the south, the storm moved westward for several days while gaining strength, aided by warm waters and decreasing wind shear. Late on 17 April, the Météo-France office on Réunion (MFR) estimated peak 10-minute winds of 250 km/h (155 mph), making Fantala the strongest tropical cyclone of the basin in terms of 10-minute sustained winds. The Joint Typhoon Warning Center (JTWC) estimated peak 1-minute winds of 285 km/h (180 mph), equivalent to Category 5 intensity on the Saffir-Simpson scale, also the strongest on record in the South-West Indian Ocean, in terms of maximum sustained wind speed. Early on 18 April, Fantala reached its peak intensity, with a minimum central pressure of 910 millibars (27 inHg).
The 2016–17 South-West Indian Ocean cyclone season was a below-average season, with five tropical storms, three of which intensified into tropical cyclones. It officially began on November 15, 2016, and ended on April 30, 2017, with the exception for Mauritius and the Seychelles, for which it ended on May 15, 2017. 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 were monitored by the Regional Specialised Meteorological Centre in Réunion, though the Joint Typhoon Warning Center issued unofficial advisories.
The 2018–19 South-West Indian Ocean cyclone season was the costliest and the most active season ever recorded. Additionally, it is also the deadliest cyclone season recorded in the South-West Indian Ocean, surpassing the 1891–92 season in which the 1892 Mauritius cyclone devastated the island of Mauritius, and is mainly due to Cyclone Idai. The season was an event of the annual cycle of tropical cyclone and subtropical cyclone formation in the South-West Indian Ocean basin. It officially began on 15 November 2018, and ended on 30 April 2019, except for Mauritius and the Seychelles, which it ended on 15 May 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.
Intense Tropical Cyclone Kenneth was the strongest tropical cyclone to make landfall in Mozambique since modern records began. The cyclone also caused significant damage in the Comoro Islands and Tanzania. The fourteenth tropical storm, record-breaking tenth tropical cyclone, and ninth intense tropical cyclone of the 2018–19 South-West Indian Ocean cyclone season, Kenneth formed from a vortex that the Météo-France office on La Réunion (MFR) first mentioned on 17 April. The MFR monitored the system over the next several days, before designating it as Tropical Disturbance 14 on 21 April. The disturbance was located in a favorable environment to the north of Madagascar, which allowed it to strengthen into a tropical depression and later a tropical storm, both on the next day. The storm then began a period of rapid intensification, ultimately peaking as an intense tropical cyclone with 10-minute sustained winds of 215 km/h (134 mph) and a minimum central pressure of 934 hPa. At that time, Kenneth began to undergo an eyewall replacement cycle and weakened slightly, before making landfall later that day as an intense tropical cyclone. As a result of land interaction, Kenneth became disorganised as it made landfall and rapidly degenerated thereafter. The storm then shifted southward, with the MFR cancelling all major warnings for inland cities. Kenneth was reclassified as an overland depression after landfall, with the MFR issuing its warning at midnight UTC on 26 April. Thunderstorm activity developed off the coast of Mozambique on 27 April as the system began drifting northward. Kenneth re-emerged off the coast of northern Mozambique on 28 April, before dissipating on the next day.
The 2020–21 South-West Indian Ocean cyclone season was an above-average season which produced 12 named storms, with 7 strengthening into tropical cyclones. The season started with the formation of Cyclone Alicia in the extreme northeast section of the basin on 12 November 2020, 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 start of the season. It officially began on 15 November 2020, and ended with the dissipation of Cyclone Jobo on 24 April, 6 days before the official end on 30 April 2021, with the exception of Mauritius and the Seychelles, which officially ended 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.
The 2021–22 South-West Indian Ocean cyclone season had the latest start on record. Despite the late start, it was an above-average season that produced 12 named storms, with five becoming tropical cyclones. The season began on 15 November 2021, and ended on 30 April 2022, with the exception for Mauritius and the Seychelles, for which it ended on 15 May 2022. 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. However, tropical cyclones that form at any time between July 1st, 2021 and June 30th, 2022 will count towards the season total. 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.
Tropical Cyclone Gombe was a strong tropical cyclone that affected Mozambique. It became the first storm to make a major landfall in Nampula Province in Mozambique since Cyclone Jokwe in 2008. The eighth tropical storm, fourth tropical cyclone and fourth intense tropical cyclone of the 2021–22 South-West Indian Ocean cyclone season, Gombe originated from a tropical disturbance located off the coast of Madagascar. This area of convection was designated by the Joint Typhoon Warning Center as Invest 97S on 6 March. The next day, it began to slowly move westward and executed a loop as it became more organized, which prompted Météo-France Reunion (MFR) to note the system as Zone of Disturbed Weather 09. The system became a depression on 9 March, and became a moderate tropical storm the same day. Soon after being named, Gombe made landfall in Madagascar, and entered in the Mozambique Channel the next day. The storm continued its westward motion while slowly intensifying, and was upgraded to a Tropical Cyclone by the MFR on 10 March. Closing in on Nampula Province, the storm underwent rapid intensification, and was upgraded to the fourth Intense Tropical Cyclone of the year and reached its peak intensity on 11 march, with maximum 10-minute sustained winds of 165 km/h (105 mph), maximum 1-minute sustained winds of 185 km/h (115 mph), and a minimum central pressure of 960 hectopascals (28 inHg). The storm proceeded to make landfall, and quickly lost its convection over land. On 12 March, Gombe degenerated into a remnant low overland. However, the system subsequently turned southeastward and reemerged over water, before briefly regenerating into a tropical depression on 17 March. Gombe dissipated later that day.
The 2022–23 South-West Indian Ocean cyclone season was one of the deadliest South-West Indian cyclone seasons on record, mostly due to Cyclone Freddy. It officially began on 15 November 2022, and ended on 30 April 2023, with the exception for Mauritius and the Seychelles, for which it ended on 15 May 2023. 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. However, tropical cyclones can form year-round, and all tropical cyclones that form between 1 July 2022 and 30 June 2023 will be part of the season. 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. The season was average in terms of the number of systems that formed, with nine systems becoming at least moderate tropical storms, and six reaching tropical cyclone strength. Activity began early, with the first two systems developing in September and October, and ended late with Fabien in May.
The 2023–24 South-West Indian Ocean cyclone season was an above-average season, including ten named storms, six tropical cyclones and two intense tropical cyclones. Despite its moderate activity, it was the least deadly and destructive season in three years. It is the current event of the annual cycle of tropical and subtropical cyclogenesis. It began on 15 November 2023, and ended on 30 April 2024, with the exception for Mauritius and the Seychelles, where it ended on 15 May 2024. 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. However, tropical cyclones can form year-round, and all tropical cyclones that formed between 1 July 2023 and 30 June 2024 would be part of the season. 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.