Cyclone Chido
Intense Tropical Cyclone Chido was a compact but very powerful, destructive, and deadly tropical cyclone which impacted Southeast Africa in December 2024. Chido, which means a desire in Shona, was the third named storm and the second intense tropical cyclone of the 2024–25 South-West Indian Ocean cyclone season. It became the strongest tropical cyclone to affect Agaléga since Cyclone Andry in 1983, and the most powerful storm to strike Mayotte in at least 90 years. It is also the costliest tropical cyclone on record in the South-West Indian Ocean basin, surpassing Cyclone Idai of 2019.
Chido originated from an elongated circulation that the Météo-France office in Réunion began monitoring on 7 December, located east of Diego Garcia. In the post-storm analysis, it was indicated that the storm had already begun forming as a zone of disturbed weather on 5 December. On 11 December, Chido rapidly deepened and intensified into an intense tropical cyclone within twelve hours, with its eye passing over Agaléga. Early the next day, the United States Joint Typhoon Warning Center upgraded the system to a Category 4-equivalent tropical cyclone, with estimated 1-minute maximum sustained winds of, while the MFR estimated its peak intensity with a minimum central pressure of and 10-minute maximum sustained winds of as it maintained its small size and moved westwards. As the system passed off the northern tip of Madagascar, the eye briefly cleared and the central dense overcast remained compact and symmetrical. Chido entered the Mozambique Channel on 14 December, with microwave imagery showing highly developed organized bands of deep convection. Satellite imagery showed cooling cloud tops surrounding a clearing eye, indicating the strengthening of the storm, and on 15 December, Chido made landfall in Pemba, Mozambique, with 10-minute sustained winds estimated at. Shortly after landfall, the MFR reported that Chido moved through Mozambique and Malawi, with convective activity gradually weakening. On 16 December, Chido degenerated into an overland depression, and the MFR issued its final advisory on the system.
The deaths of at least 173 people are attributed to Chido; 120 in Mozambique, 40 in Mayotte and 13 in Malawi, along with over 5,194 injuries. Agaléga was significantly affected by Chido, with over 95% of the territory's buildings destroyed. Little was done to prepare for the storm in Mayotte, which experienced catastrophic damage and a heavily debated number of deaths and missing from Chido. Numerous residents were unaccounted for, with most shanty towns completely destroyed and 85% of the island being left without power by 16 December. In Mozambique, over 155,500 homes were badly affected and entire communities were destroyed. Relatively minor damage also occurred in the Comoros and Madagascar. Economic losses from Chido reached $3.9 billion, making it the costliest tropical cyclone in the South-West Indian Ocean basin.
Meteorological history
Cyclone Chido originated from an elongated circulation that the Météo-France office in Réunion began monitoring on 7 December, located east of Diego Garcia. In the post-storm analysis, it was indicated that the storm had already begun forming as a zone of disturbed weather on 5 December. On 8 December, at 08:00 UTC, the United States Joint Typhoon Warning Center issued a tropical cyclone formation alert, noting a consolidating low-level circulation center and a favorable environment with low wind shear and sea surface temperatures exceeding. The following day, the JTWC began issuing warnings for the system, classifying it as Tropical Cyclone 04S, as satellite imagery showed a partially exposed low-level circulation center on the eastern side of a developing burst of deep convection, which was nearly circular in shape and had cloud tops cooler than. At 00:00 UTC on 10 December, the MFR reported that the system had intensified into a moderate tropical storm, with the Mauritius Meteorological Services naming it Chido, as convection strongly increased around the center of the system, accompanied by cooling of cloud tops and an expansion of the central dense overcast. The cyclone moved westward, and the MFR reported that it quickly intensified into a severe tropical storm around 12:00 UTC that day, citing the Dvorak technique—a method used to determine a tropical cyclone's intensity based on its satellite appearance. On the subsequent day, Chido significantly improved in organization, with satellite imagery showing a newly developed eye feature, an increasingly symmetric structure, and curved convective banding wrapping around the system. As a result, MFR upgraded it to a tropical cyclone, and the JTWC followed suit.Chido rapidly deepened and intensified into an intense tropical cyclone within twelve hours, with its eye passing over Agalega and bringing extreme conditions to the island, where a minimum pressure of was recorded. This made Chido the strongest tropical cyclone to directly affect the island since Cyclone Andry in 1983. Early the next day, the JTWC upgraded the system to a Category 4-equivalent tropical cyclone, with estimated 1-minute maximum sustained winds of, while the MFR estimated its peak intensity with a minimum central pressure of and 10-minute maximum sustained winds of as it maintained its small size and moved westwards. After reaching its peak intensity, the cyclone's eye, which was wide, became cloud-filled and increasingly ragged, and on 13 December, an eyewall replacement cycle occurred, causing the storm to weaken. As the system passed about off the northern tip of Madagascar, the eye briefly cleared and the CDO remained compact and symmetrical. Chido entered the Mozambique Channel on 14 December, with microwave imagery showing highly developed organized bands of deep convection. As it neared Mayotte, it quickly re-intensified, with Pamandzi Airport recording a maximum gust of, setting an all-time record for the station, and a minimum pressure of, breaking the previous record of set during Cyclone Kamisy in 1984. Additionally, the MFR reported that it was the strongest storm to strike Mayotte in at least 90 years. Satellite imagery showed cooling cloud tops surrounding a clearing eye, indicating the strengthening of the storm, and at 06:00 UTC on 15 December, Chido made landfall on Pemba in Mozambique, with 10-minute sustained winds estimated at. Shortly after landfall, the JTWC discontinued warnings, and the MFR reported that Chido moved through Mozambique and Malawi, with convective activity gradually weakening. On 16 December, Chido degenerated into an overland depression, and the MFR issued its final advisory on the system.
Preparations
Mauritius and Madagascar
In Agaléga, residents sought refuge at an airport terminal.In Madagascar, officials said that although damage from Chido would likely be minor, due to the characteristics of the cyclone and the capacity of the area expected to be affected, access to the north of the island would be challenging as national roads were still damaged from previous cyclones. However, the National Office for Risk and Catastrophe Management deployed food stocks to northern Madagascar, in addition to the stocks already available through partners. UNICEF planned to mobilize a United Nations Humanitarian Air Service flight to preposition items in the north where stock levels are relatively low. OCHA, in support of BNGRC, conducted a refresher training on aerial and rapid multi-sector needs assessment for about 40 inter-agency teams, which would be mobilized at any time if a post-cyclone assessment was needed. Madagascar Red Cross branches were alerted, disaster response teams were identified and early warning system equipment was deployed. Humanitarian partners continued to monitor the situation to assess required support. Three teams of BNGRC were deployed to Antsiranana, Vohemar and Ambilobe to support anticipatory actions conducted at a local level including preventive evacuations. The Red Cross also carried out awareness-raising campaigns in Sava and Sofia Regions through its crisis modifier window.
Comoros and Mayotte
On 13 December, Météo-France issued a red alert for Mayotte, before revising the alert level to purple the following day. However, most residents of the island ignored the warnings in the 24 hours before the storm hit, underestimating its severity. Some chose to remain in their homes out of fear that they may be looted, while others avoided shelters out of fear of deportation, as about a third of residents in Mayotte are undocumented migrants. Meteorological officials in the Comoros issued an orange weather alert that would be issued on 13 December. On that day, the Direction Générale de la Sécurité Civile decreed the official activation of the Cyclone-induced Flood Rescue Plan and the national emergency operational centre would help monitor the storm's effects. The Comorian Red Cross in Anjouan and Mohéli were confined during the cyclone's passing. Residents were also advised to follow forecasts through their national meteorological service. Prince Said Ibrahim International Airport was closed from 13 to 16 December.Southern Africa
The United Nations Office for the Coordination of Humanitarian Affairs said that over 1.7 million people in Mozambique could be affected by winds exceeding, and that the cyclone may exacerbate a cholera outbreak affecting the country. The Mozambique National Institute of Meteorology issued red alerts for Cabo Delgado and Nampula Provinces and recommended that all civilians must take precautionary and safety measures. The Mozambique Red Cross Society and World Food Programme implemented anticipatory actions following the activation by the Technical Council for Disaster Management for Mogincual and Angoche Districts. Partners also conducted an assessment mission in Cabo Delgado, visiting accommodation sites to provide inputs in the updated list of accommodation centers.In Malawi, the Department of Climate Change and Meteorological Services issued a warning for 15 districts expected to be in the path of Chido. Some districts were forecast to receive over of rain within 24 hours, with possibilities of flooding, strong winds and damage to infrastructure. The Department of Disaster Management Affairs convened daily meetings in response to the cyclone's potential impact. On 14 December, the DoDMA agreed that a centralised Emergency Operation Centre would be set-up in Blantyre and remain operational from 15 December. The country's government initiated the district response coordination mechanism to scale up the preparedness efforts. All response sectors, including the drone team, were activated and are in progress of prepositioning key response stocks in strategic areas in southern Malawi.
Authorities in Zimbabwe said that Chido was likely to affect the country by 17 December, with heavy rainfall, flooding and landslides likely. OCHA also reported that Chido may exacerbate rainfall in Angola, Botswana, the Democratic Republic of the Congo, Eswatini, Tanzania and South Africa.