Indian Ocean: Intense Tropical Cyclone Emnati tracking westward Feb. 20; landfall forecast in east-central Madagascar late Feb. 22 /update 3

Event

Tropical Cyclone Emnati has strengthened into an intense tropical cyclone and is tracking westward in the Indian Ocean Feb. 20. As of 09:00 MUT, the storm's center of circulation was approximately 354 km (220 miles) north-northwest of Port Louis, Mauritius. Forecast models indicate the system will strengthen further as it tracks in a west-southwestward direction north of Mauritius and Reunion Feb. 20-21. Emnati is moving past Mauritius and at its closest was around 320km (199 miles) northwest of Grand Bay, and will pass Reunion around 350km (217 miles) to the north late Feb. 20-early Feb. 21. Strong winds, rough seas, and heavy rainfall will likely be felt across Reunion and parts of Mauritius through at least Feb. 21. Emnati is then forecast to track southwestward toward Madagascar's eastern coast, making landfall as an intense tropical cyclone over east-central Madagascar, between Mahanoro and Mananjary, late Feb. 22. The storm system is subsequently likely to weaken into a severe tropical storm as it tracks southwestward over southern Madagascar Feb. 22-23. The system will then likely move into the Mozambique Channel Feb. 24 as a moderate tropical storm and is expected to strengthen slightly as it tracks south-southwestward into the Indian Ocean Feb. 24-25. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Mauritius' Sir Seewoosagur Ramgoolam International Airport (MRU) suspended operations from late Feb. 19 until further notice. Reunion's Roland Garros Airport (RUN) suspended all flights from 13:30 RET Feb. 20 until further notice. Schools and other educational institutions will be closed in both Mauritius and Reunion Feb. 21. In Reunion, around 1,500 people were without power as of Feb. 20 due to downed power lines. Authorities have closed a number of roads from late Feb. 20, including sections of Route du Littoral, Route Cilaos, and Route Salazie, as a precaution due to possible coastal flooding during the passing of Emnati.

Government Advisories
As of Feb. 20, the Mauritius Meteorological Services has lifted all cyclone warnings as the storm moves away northwest of the islands; however, a strong wind and high waves warning is still in effect for Mauritius through early Feb. 21. A strong swell warning is also in effect for Agalega Island through late Feb. 21 and a swell warning is in effect for Rodrigues Island through early Feb. 21. Strong winds, with gusts of up to 90 kph (56 mph) will persist in places across Mauritius through Feb. 21 and swells of around 5 meters (16 feet) are expected for the coastline of Mauritius and beyond the reefs in Rodrigues Island. Swells of 3-4 meters (10-13 feet) are expected in the seas around Agalega Island.

Meteo France La Reunion has issued an orange cyclone alert (the second highest level on a four-tier scale) across the territory and authorities have announced the territory will move to the highest red alert level from 21:00 RET Feb. 20. 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 late Feb. 20-early Feb. 21. A red heavy swell warning (the highest level on a two-tier scale) has been issued along the north, northeast, and east coast and orange warnings have been issued for the southeast and northwest coast. 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 Antanambao, Atsimo-Atsinanana, Brickaville, Fitovinany, Mahanoro, Manampotsy, Marolambo, Vatomadry, and Vatovavy regions and districts. Green cyclone alert warnings have been issued for Alaotra Magoro, Amoron'i Mania, Analanjirofo, Andramasina, Anjozorobe, Anosy, Antananarivo, Avaradrano, Ihorombe, Manjakandriana, Matsiatra Ambony, Toamasinia I-II, and Vakinankaratra regions and districts. A red heavy swells and strong wind warning (the 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.