On the weekend of December 15, 2024, Cyclone Chido swept across the Mayotte archipelago with gusts reaching 226 km/h. The damage is considerable and the toll, currently set at 20 dead, is very likely to increase. How could such a depression have formed?
A disaster. This weekend, Mayotte was devastated by a depression unprecedented since the 20th century. Chido swept across the archipelago, probably doing “hundreds dead” and destroying a large part of the poorest neighborhoods in the department.
The result is a major crisis situation, where the lack of water, access to care and communication networks make relief operations very difficult. From November, Weather France explained that there was very little chance that the upcoming hurricane season would be “low risk”.
A point for the season
From November, Weather France took stock of the upcoming hurricane season, from 2024 to 2025. The forecasting organization estimated between 9 and 13 the number of systems that could develop. That is to say, storms and cyclones combined. Among them, 4 to 7 were likely to become cyclones.
With this Weather France estimated at 50% the risk of facing a “active season”, compared to only 10% for the risk of “not very active season”. Between two, there remained a 40% risk of facing a season close to normal.
Rising water temperatures
Cyclones are immense depression systems, with very low pressure. Like all cloud systems, they arise from steam.
And this year, climate change requires, the water in the seas and oceans has evaporated a lot : “Warmer than normal sea temperatures and intense rain-storm activity are expected,” the organization predicted.
Et Weather France anticipated: “Unlike the last 3 hurricane seasons where we had to wait until January to experience the first impacting systems, these potential impacts could begin earlier, possibly before the end of 2024.”
Hit hard
It was with this report that the season began. The risks were high, but not inevitable. Also, the situation was closely monitored. Until a few days ago, when Chido's trajectory and scale became clearer. The archipelago was placed on orange alert on Thursday, red on Friday, and purple a few hours before the disaster.
The scale of the cyclone is not unprecedented. But its impact yes. Such powerful storms have formed in the region before, but rarely, if ever, has the archipelago found itself in the eye of the storm.
During the night from Friday to Saturday, wind gusts reached 226 km/h. The epilogue of the event is tragic: already 20 people have been declared dead, and the prefecture fears that the number will reach “several hundred”, even “thousands”.
