Indian Ocean: Tropical Cyclone Batsirai tracking southwestwards in the Indian Ocean early Feb. 2 /update 4

Event

Tropical Cyclone Batsirai has strengthened into an intense tropical cyclone and is tracking southwestwards in the Indian Ocean early Feb. 2. As of 04:00 MUT, the storm's center of circulation was approximately 246 km (152 miles) north-northeast of Port Louis, Mauritius. Forecast models indicate the system will maintain its intense tropical cyclone strength as it passes north of Mauritius Feb. 2 and Reunion Feb. 3. Although the center of the storm will pass some 150-250 km (93-155 miles) north of the islands, they will likely be impacted by the outer winds of the storm system as it passes. After passing north of the islands, the storm is forecast to track westwards Feb. 3-4 before again tracking southwestwards towards the eastern coast of Madagascar Feb. 4-5. Batsirai is forecast to make landfall over central Madagascar's east coast Feb. 5. The storm system will weaken to a tropical storm as it tracks over central Mozambique before emerging in the Mozambique Channel, where it will begin to impact the east coast of Mozambique. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Minor disruptions have been reported in Mauritius early Feb. 2. Western Old Pailles Road, the Highway to Bois Marchand, and Royal Road are either partially or completely blocked by fallen debris. A tree fell on a home on the outskirts of Port Louis and the Central Electricity Board (CEB) has suspended repairs due to the adverse weather. Sir Seewoosagur Ramgoolam International Airport (MRU) closed late Feb. 1 until further notice due to the approach of the storm. Flights at Roland Garros Airport (RUN) on Reunion have been canceled from late. Feb. 2 until further notice. Schools and universities have also been closed in the territory as a precaution.

Government Advisories
As of early Feb. 2, the Mauritius Meteorological Services has issued a Class 4 cyclone warning (the highest level on a four-tier scale) for the main island of Mauritius. Wind gusts of over 120 kph (75 mph) have been recorded in some areas of the north and northwest of the island. Moderate-to-heavy rains are forecast to persist over the island.

Meteo France La Reunion has issued an orange cyclonic alert (the second highest level on a four-tier scale) across the territory due to the approach of the storm system. Authorities have announced the alert level will be upgraded to the highest red level from 19:00 RET Feb. 2, with residents advised to shelter at home from this time. Weather conditions are expected to deteriorate late Feb. 2 and are not expected to improve till late Feb. 3 into Feb. 4. Wind gusts of over 120 kph (75 mph) are forecast in coastal areas and 150 kph (93 mph) over mountainous regions. Heavy rainfall is expected across the territory and waves exceeding 5 meters (16 feet) are expected across northern, eastern, and southern coastal areas. Coastal roads could be subject to flooding and a yellow flood alert (the lowest level on a three-tier scale) has been issued for the Langevin River.

The Madagascar General Directorate of Meteorology has warned that the cyclone is likely to make landfall on the east coast between Vatomandry and Mananjary Feb. 5. Green pre-warning alerts have been issued for the following districts: Analanjirofo, Atsinanana, Alaotra Mangoro, Vatovavy, Fitovinany, Atsimo Atsinanana, Analamanga, Itsay, Bongolava, Vakinankaratra, Amoron'i Mania, Matsiatra Ambony, Ihorombe, Antalaha, Mandritsara, Tsaratanana, and Taolagnaro. Strong winds are being experienced at sea as of Feb. 2 and seafarers are advised not to venture out to sea.

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)