The tropical cyclone season in the Indian Ocean is now underway. The first named storm, Ana, last week caused heavy rain, flooding and a number of casualties in Madagascar and other southern African countries including Mozambique, Malawi and Zimbabwe.
Madagascar is now bracing for a more intense tropical cyclone, Batsirai. It is currently the equivalent of a strong category 3 Atlantic hurricane and may intensify before landfall to Category 4 strength, with sustained winds of nearly 200 km/h.
WMO’s regional tropical cyclone centre La Réunion (Météo-France) describes Batsirai as “very dangerous.” It will make landfall in Eastern Madagascar on Saturday in the region of Mahanoro (150 km radius of uncertainty).
It will weaken upon landfall and then reintensify back in the Mozambique channel. On the current trajectory, it will curve away from Mozambique.
Batsirai brought high winds and heavy rainfall to Mauritius and La Reunion, which was placed under respectively a top-level class 4 and red alert. Parts of inland La Réunion received 1000 mm in 30 hours (8 bathpools per m2).
Waves at sea are forecast to reach 8 meters and up to 15 meters high. A storm surge of up to 1.50 meters is possible in worst hit coastal areas upon landfall. Coastal inundation risk is medium to locally high.
Batsirai will bring high rainfall totals to the east coast of Madagascar. This will widely see 50-100 mm of rain fall late Friday with the main bulk falling through Saturday, when a further 300 mm (400-600 mm on the Ankaratra mountain upslopes) could accumulate through the day. Widespread rainfall of 150-300 mm is signalled, with possible peaks of 500-600 mm.
Météo Madagascar has been providing daily assessments to both Government and humanitarian stakeholders to facilitate forward planning and anticipatory action.
The Office for the Coordination of Humanitarian Affairs (OCHA) said that preparations, under the Government of Madagascar’s leadership, include the pre-deployment of search and rescue capacity and response teams to areas likely to be impacted, aircrafts being placed on standby to support rapid assessment and response, and local purchases of humanitarian supplies to increase available stocks.
The World Food Programme warned that 600,000 people could be affected.
Batsirai will exacerbate the humanitarian situation which is already precarious after tropical storm Ana. At least 131,000 people were affected across Madagascar, including 71,000 people who were displaced, according to authorities. At least 48 people have died, almost all of them in the capital, where traditional houses collapsed, and others were swept away by landslides.
Madagascar & Southern Mozambique should be near the height of the wet season but have experienced dry conditions when compared to what would normally be expected at this time of year. Because of the very dry ground, there is an increased the risk of flash flood, landslides during any extreme rainfall events.