Madagascar: Moderate Tropical Storm Cheneso makes landfall over Sava Region Jan. 19 /update 3

Event

Moderate Tropica Cheneso made landfall over the coast of Sava Region, Madagascar, north of Antalaha during the morning of Jan. 19 and is tracking southwestward across northern Madagascar. As of 09:00 EAT, the storm's center of circulation was approximately 596 km (370 miles) northeast of Antananarivo, Madagascar. Forecast models indicate the system will weaken as it tracks southwestward over northern and into central Madagascar Jan. 19-20, before dissipating early Jan. 21. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of early Jan. 19, the Madagascar General Directorate of Meteorology has issued red cyclone alerts (the highest level on a three-tier scale) for Analanjirofo, Diana, and Sava regions, as well as yellow cyclone alerts for Alaotra-Mangoro, Atsinanana, and Sofia regions. Heavy rainfall of 10-20 cm (4-8 inches) in 24 hours is forecast across northern and central Madagascar and strong winds gusting up to 120 kph (75 mph) are possible in the vicinity of where the storm made landfall. Adverse weather conditions are expected to persist through at least Jan. 22. Authorities have issued yellow heavy rain warnings for Analamanga, Betsiboka, Boeny, Fitovinany, and Vatovavy regions, red strong wind and strong swell warnings from Cap d' Ambre to Mahanoro, and green strong swell warnings from Toamasina to Mananjary. Vessels are advised to avoid going to sea between Cap d'Ambre and Mahanoro. Authorities will likely publish new advisories or update/rescind existing alerts 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 airports in the region 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. 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