Madagascar: Tropical Storm Gamane tracking southwestward over southern Diane Region as of early March 28 /update 4

Moderate Tropical Storm Gamane is tracking southwestward over southern Diane Region early March 28, having made landfall as a tropical cyclone in Vohemar District, Sava Region, early March 27. As of 06:00 EAT, the storm's center of circulation was approximately 572 km (356 miles) north-northeast of Antananarivo, Madagascar.

Forecast models indicate the system will weaken into a tropical depression as it turns to track south-southeastward and then southeastward over northeastern Sofia Region through March 28, then far northern Analanjirofo and Sava regions before exiting into the Indian Ocean the afternoon of March 29. The system will strengthen back into a moderate tropical storm as it tracks southeastward away from Madagascar March 29-31 before making landfall over Mauritius main island early April 1. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of early March 28, Meteo Madagascar is maintaining blue cyclone alerts for the Diane, Sava, and Analanjirofo regions. Red heavy rainfall warnings have been issued for Amparafaravola and Andilamena districts in Alaotra-Mangoro Region, Belalanana, Befandriana-Nord, and Mandritsara districts in Sofia Region, and Toamasina and Vohibinany districts in Atsinanana Region. Yellow heavy rainfall warnings have been issued for the Analalava and Antsohihy districts in the Sofia Region, and green heavy rainfall warnings are in place across the rest of Atsinanana Region and Ambatondrazaka and Anosibe An'ala districts in Alaotra-Mangoro Region. Red strong wind and heavy swell warnings are in place for much of Madagascar's eastern, northeastern, and southern coastlines. Maritime operators are advised not to venture out to sea between Antsiranana and Mahanoro, as well as between Analalava and Antsiranana, due to dangerous sea conditions. Severe weather is ongoing across much of northern and northeastern Madagascar as of early March 28 and the heavy rainfall is expected to persist through at least March 28.

Reports indicate flooding is affecting parts of Sava Region, including the towns of Antalaha, Sambava, and Vohemar. Several homes in the region have been inundated by floodwaters. Several roads across northern Madagascar are impassable, including parts of national roads 5 and 6. Damage assessments may take some time due to the ongoing severe weather associated with Gamane.

The Mauritius Meteorological Service has issued a severe weather warning advising that severe weather is possible over Mauritius March 30-April 1, depending on the evolution of the storm system.

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.