Indian Ocean: Tropical Cyclone Batsirai tracking southwestwards across Madagascar the afternoon of Feb. 6 /update 11

Event

Tropical Cyclone Batsirai is tracking west-southwestwards across Madagascar as of the late afternoon of Feb. 6, following landfall over Mananjary District on the east coast around 20:00 Feb. 5. As of 15:00 EAT, the storm's center of circulation was approximately 437 km (272 miles) east of Europa Island. Forecast models indicate the system will continue weakening into a moderate tropical storm as it tracks southwest across central Madagascar before emerging into the Mozambique Channel, north of Toliara, Atsimo Andrefana Region, late Feb. 6. Batsirai is forecast to maintain its strength as it tracks southwestwards then southwards in the Mozambique Channel through early Feb. 9, with no further landfall forecast. However, some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Disruptions occurred in Mauritius and Reunion as the storm passed north of the islands Feb. 2-4. Flights are operational at Sir Seewoosagur Ramgoolam International Airport (MRU) in Mauritius. In Reunion, at least 12 people were injured in storm-related incidents. Power outages occurred nationwide, and as of late Feb. 5, around 20,000 people were still without power, mostly in the municipalities of Cilaos, Hauts de Saint-Paul, Saint-Joseph, and Salazie. More than 140,000 people are also estimated to be without water supply in the western and southern municipalities. Schools will remain closed until Feb. 7. Flights at Roland Garros Airport (RUN) are operational. The RN5 Route de Cilaos remains closed with temporary opening 17:00-18:00 Feb. 6.

Madagascar is still recovering from the passage of Tropical Storm Ana which transited over the country Jan. 22, causing widespread flooding. Authorities began pre-emptive evacuations in Manakra Feb. 4. At least 40,000 people mostly from Analamanga, Atsinanana, Vatovy, Fitovinany, and Atsimo Atsinanana regions have been evacuated to 151 evacuation shelters across the country. Authorities have cut the power supply in Manakara, Ambositra, Ranomafana, Manandriana, Ikongo, and Ambato Boeny as a precaution. Schools have been closed since Feb. 4, and all nonessential workers have been advised not to work in areas under red alert warnings.

Government Advisories
The Mauritius Meteorological Services has lifted all cyclone warnings following the passing of the storm.

Meteo France La Reunion remains in a backup phase cyclonic alert across the territory as of late Feb. 6, with residents advised to avoid nonessential travel until authorities lift this phase. All weather warnings have been lifted, however.

The Madagascar General Directorate of Meteorology has warned of waves of 4-12 meters (13-39 feet) on the southeast, south, and west coasts. Authorities issued warnings for rainfall totals of up to 10cm (4 inches) and possible widespread flooding in Matsiatra Ambony Region, as well as in Taolagnaro, Iakora and Ivhibe, in Ihorombe Region. Authorities have also warned of heavy rain in areas on the southwest coast, and as of the afternoon of Feb. 6 are maintaining the following warning:

• Red level imminent danger alerts (the highest level on a three-tier scale): Areas along the Fiherenana River in Atsimo Andrefana Region, and areas along the Mananjary River and Pangalane Canal in Vatovavy Region.

Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.

Advice

Activate contingency plans in areas where officials forecast tropical storm conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge.

Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center
Mauritius Meteorological Services
Madagascar General Directorate of Meteorology (French)
Meteo France Reunion (French)