Indian Ocean: Tropical Cyclone Gamane tracking west-southwestward off the northeast coast of Madagascar as of early March 27 /update 2

Tropical Cyclone Gamane has intensified significantly and is tracking west-southwestward off the northeast coast of Madagascar early March 27. As of 06:00 EAT, the storm's center of circulation was approximately 722 km (449 miles) north-northeast of Antananarivo, Madagascar.

Forecast models indicate the system will make landfall as a tropical cyclone over Sava Province north of Vohemar over the coming hours before tracking southwestwards across the northern part of the province through early March 28. The system is forecast to weaken into a severe tropical storm as it gradually turns to track southwards, then southeastwards across the western and southern parts of Sava Province before moving back into the Indian Ocean early March 29 and track southeastward away from Madagascar through March 30. Gamane is likely to weaken further into a moderate tropical storm as it tracks toward the Mascarene Islands and makes a close approach to Mauritius early April 1, passing just northeast of the main island. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of early March 27, Meteo Madagascar has issued red cyclone alerts (the highest level on a three-tier scale) for Diane and Sava regions and yellow cyclone alerts for Analanjirofo Region. Yellow heavy rainfall warnings have been issued across the Atsinanana Region, and Belalanana, Befandriana, and Mandritsara districts of the Sofia Region, and green heavy rainfall warnings are in place across the Alaotra-Mangoro Region. Red strong wind and heavy swell warnings are in place for much of Madagascar's eastern, northeastern, and southern coastlines. Weather conditions are reportedly already deteriorating in northern and northeastern parts of the country and will spread into east central and eastern regions over the coming days. Heavy rainfall is expected to persist in parts of Analjirofo, Diane, and Sava regions through at least March 28 and could trigger widespread flooding and landslides in affected areas. Storm surge is possible in coastal areas of Sava March 27 as the system approaches land; authorities have advised maritime operators not to venture out to sea between Antsiranana and Mahanoro, as well as between Analalava and Antsiranana, due to dangerous sea conditions.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible. The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports 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. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.