Indian Ocean: Tropical Storm Dumako tracking westwards in the Indian Ocean Feb. 15 /update 2

Event

Tropical Storm Dumako is tracking westwards in the Indian Ocean Feb. 15. As of 09:00 EAT, the storm's center of circulation was approximately 378 km (235 miles) northeast of Antananarivo, Madagascar. Forecast models indicate the system will pass over St. Marie Island at around 13:00 EAT Feb. 15 before going on to make landfall over Analanjirofo Region a few hours later. Dumako is then likely to weaken rapidly as it tracks westwards across northern Madagascar, dissipating over Melaky Region late Feb. 16. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

The Madagascar General Directorate of Meteorology has warned heavy rainfall of more than 16 cm (6 inches) is likely in Analanjirofo Region, as well as winds of 65-70 kph (40-43 mph). People between Brickaville and Vohemar are advised not to go out to sea as weather conditions are likely to gradually deteriorate. As of early Feb. 15, the following alerts have been issued regarding Dumako:

• Red imminent danger alert (the highest level on a three-tier scale): Analanjirofo Region.

• Yellow threat alerts: Sava Region and Toamasina I and Toamasina II, Befandriana, Avaratra, Mandritsara, Andilamena, Amparafaravola, and Ambatondrazaka districts.

• Green warning alerts: Diana Region and Brickaville and Bealanana districts.

• Red heavy swell vigilance: central and northeast coasts between Sambava and Brickaville.

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

Madagascar is still recovering from recent heavy rains and the passage of tropical cyclones Ana and Batsirai. Tropical Cyclone Ana resulted in at least 58 fatalities while Tropical Cyclone Batsirai killed at least 121 people. Some places remain flooded. Additional rainfall and strong winds could exacerbate the situation, especially in areas still recovering from the previous storms.

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 airports in the region, such as Antananarivo's Ivato International Airport (TNR), Fascene Airport (NOS), and Sainte Marie Airport (SMS), 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
Madagascar General Directorate of Meteorology (French)