Mayotte: Cyclone Chido expert reaction

A tropical cyclone has hit the French island of Mayotte, leading to the deaths of several hundred people. 

University of Reading meteorologists have provided expert comment.

Dr Alex Baker said: “Cyclone Chido underwent rapid intensification before landfall in Mauritius, weakened slightly, and then regained its Category 4-equivalent intensity before reaching Mayotte and continuing to Mozambique. 

“Rapid intensification events are typically less well forecast, so that can be a factor in the delivery of early warnings to communities. In Chido’s case, the track of the cyclone was quite well forecast, with the key landfall areas and the possibility of re-intensification being identified in warnings several days ahead, but the peak intensity was somewhat underestimated. 

“As for climate change, the kinds of conditions that lead to rapid intensification have become increasingly prevalent over recent decades. We should wait for more analysis before making any statements about how much the intensity of Chido was affected by climate change, but higher rainfall rates and peak wind speeds are expected in a warming climate. 

“Much of the devastation is due to a lack of resilience of low-income communities there. The University of Reading is involved in a research programme to improve resilience and preparedness for tropical cyclones across Southern Africa. It is hoped that this programme will help better understand cyclone risk across the region.”

Dr Helen Hooker said: “The path of tropical cyclone Chido was well forecast days ahead of its landfall and crossing of Mayotte. Sadly, the impacts have been catastrophic. On a small island, it’s incredibly difficult to find safe places to relocate people to when a storm of this ferocity approaches. This is made more difficult when the capacity to build resilient infrastructure is limited. 

“There’s evidence that climate change is making very intense tropical cyclones like Chido more likely to happen. Investment into improving early warnings of extreme weather, communication systems and actions to prevent loss of life and livelihoods should be a priority for national leaders. 

“Indian Ocean temperatures have been incredibly high this year, contributing to the strengthening of tropical cyclone Chido into a Category 4 storm with wind speeds of more than 225 km/h (140 mph).

“Impacts from coastal storm surge and heavy rainfall have caused flooding in Mozambique. As Chido continues to track further inland today, southern Malawi will also experience very heavy rainfall and strong winds.”

Professor Liz Stephens said: "The intensity of tropical cyclones in the South West Indian Ocean has been increasing, this is consistent with what scientists expect in a changing climate - warmer oceans fuel more powerful storms.

"Even though the path of Cyclone Chido was well forecasted several days ahead, communities on small islands like Mayotte don't have the option to evacuate - there's nowhere to go.

“The tragic impacts of Cyclone Chido in Mayotte really show how vulnerable small islands are to climate change. A single storm can severely damage critical infrastructure like power, water supply and communications across an entire island, making international support essential.

“Small islands must be supported to build resilience to tropical cyclones. It is not enough to just improve early warning systems, we must improve the resilience of homes and critical infrastructure to ensure that people have somewhere safe to shelter and essential services are operational during and after the storm.

“Countries like Bangladesh have dramatically reduced the number of fatalities from tropical cyclones by building evacuation shelters to provide communities with somewhere safe to go when the early warning is issued. This kind of success must be replicated around the world to protect communities vulnerable to climate change."