Indian Ocean: Intense Tropical Cyclone Emnati tracking west-southward Feb. 21; landfall forecast in east-central Madagascar late Feb. 22 /update 4

Event

Intense Tropical Cyclone Emnati is tracking west-southwestward in the Indian Ocean Feb. 21. As of 10:00 RET, the storm's center of circulation was approximately 344 km (214 miles) north-northwest of St. Denis, Reunion. Forecast models indicate that the system will maintain intense tropical cyclone strength as it tracks in a west-southwestward and then southwestward toward Madagascar's eastern coast, making landfall over east-central Madagascar, between Mahanoro and Manakara, late Feb. 22. The storm system is likely to weaken into a severe tropical storm as it tracks southwestward over southern Madagascar from Feb. 22-23. The system is expected to move into the Mozambique Channel Feb. 24 as a moderate tropical storm. It is expected to strengthen slightly as it tracks south-southwestward and then southwards into the Indian Ocean Feb. 24-26. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Disruptions have been reported across parts of Mauritius and Reunion as the storm system passed to the north of the islands Feb. 19-21. Mauritius' Sir Seewoosagur Ramgoolam International Airport (MRU) suspended operations late Feb. 19-late Feb. 20. Reunion's Roland Garros Airport (RUN) suspended all flights from 13:30 RET Feb. 20 and is scheduled to resume flights from 15:00 Feb. 21. Schools and other educational institutions are closed in both Mauritius and Reunion Feb. 21. In Reunion, around 2,000 people are without power as of Feb. 21 due to downed power lines and around 3,400 are without water supply. Route du Littoral will remain closed until at least Feb. 22.

Government Advisories
As of Feb. 21, the Mauritius Meteorological Services has lifted all cyclone warnings; however, a strong swell warning is in effect for Agalega Island through Feb. 22 and for Mauritius and Rodrigues island Feb. 21. Swells of around 5 meters (16 feet) are expected off the coast of Mauritius and 3-4 meters (10-13 feet) in the seas around Agalega and Rodrigues islands.

Meteo France La Reunion has issued a cyclone backup phase alert across the territory following the passing of the storm. Heavy rainfall, strong winds, and rough seas are forecast to impact the territory through at least Feb. 21. Orange level rainfall, thunderstorms, and strong wind warnings (the middle level on a three-tier scale) are in place across the territory. A red heavy swell warning has been issued along the north and northeast coast, and orange warnings have been issued for the east and northwest coasts. Swells of 5-6 meters (16-20 feet), resulting in the highest waves of up to 10 meters (33 feet), are expected in the seas around Reunion. Conditions are forecast to begin to improve from late Feb. 21-Feb. 22.

The Madagascar General Directorate of Meteorology has issued yellow cyclone threat warnings (the middle level on a three-tier scale) for Ambohitra, Amoron'i Mania, Analanjirofo, Andramasina, Anosy, Antananarivo Atsimondrano, Antananarivo Avaradrano, Antananarivo Renivohitra, Arivonimamo, Atsimo-Atsinanana, Atsinanana, Fitovinany, Ihorombe, Manampotsy, Mangoro, Manjakandriana, Matsiatra Ambony, Vakinankaratra, and Vatovavy regions and districts. Green cyclone alert warnings have been issued for Alaotra, Androy, Anjozorobe, Ankazobe, Atsimo Andrefana, Bongolava, Menabe, Miarinarivo, and Soavinandriana regions and districts. A red heavy swell warning (the highest level on a three-tier scale) has been issued along the east coast of Madagascar, and a yellow warning has been issued for the rest of the coastline.

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 airports in affected areas and temporary closures of ports are also possible.

Stagnant pools of water during and after flooding may increase the incidence of 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 or tropical cyclone 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.