Indian Ocean: Severe Tropical Storm Emnati tracking west-southwestward in the Indian Ocean Feb. 19 /update 2

Event

Severe Tropical Storm Emnati is tracking west-southwestward in the Indian Ocean Feb. 19. As of 16:00 MUT, the storm's center of circulation was approximately 420 km (261 miles) north-northeast of Port Louis, Mauritius. Forecast models indicate the system will strengthen into a tropical cyclone over the coming days as it tracks in a southwestward direction, passing to the north of Mauritius and Reunion Feb. 20-21. Although Emnati's center of circulation is currently forecast to track far to the north of Mauritius and Reunion, the islands are likely to be impacted by strong winds, rough seas, and heavy rainfall as the storm system passes. Emnati is then forecast to continue to track southwestward toward Madagascar's eastern coast, making landfall as a tropical cyclone over east-central Madagascar, between Mahanoro and Mananjary, late Feb. 22. The storm system is subsequently likely to weaken into a moderate tropical storm as it tracks southwestward over southern Madagascar Feb. 22-23; the system will then likely move into the Mozambique Channel Feb. 24. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Ahead of Emnati's approach, Mauritius' Sir Seewoosagur Ramgoolam International Airport (MRU) has announced that it will be closed from late Feb. 19 until further notice. Reunion's Roland Garros Airport (RUN) will suspend all flights after 13:30 RET Feb. 20, with some flights scheduled for after this time being brought forward and others canceled. Schools and other educational institutions will be closed in Reunion Feb. 21.

Government Advisories
As of Feb. 19, the Mauritius Meteorological Services has issued a class four cyclone warning (the highest level on a four-tier scale) for Mauritius. All cyclone warnings have been lifted for Rodrigues Island; however, a strong wind and swell warning is still in effect for the island. Heavy rainfall, thunderstorms, strong winds, and rough seas are forecast to impact the islands over the coming days. Rough seas are likely and flooding is possible in coastal areas at high tide.

Meteo France La Reunion has issued a yellow cyclone pre-alert (the lowest level on a four-tier scale) across the territory. Heavy rainfall, strong winds, and rough seas are forecast to impact the territory through at least Feb. 21. Wind gusts could reach 120 kph (75 mph) in coastal areas and up to 140 kph (87 mph) in mountainous areas.

The Madagascar General Directorate of Meteorology has issued green pre-warning alerts (the lowest level on a three-tier scale) for Analanjirofo, Atsimo-Atsinanana, Atsinanana, Fitovinany, and Vatovavy regions. A yellow heavy swells and strong wind warning (the second-highest level on a three-tier scale) has been issued along the entire east coast of Madagascar.

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.