Mozambique Channel: Severe Tropical Storm Dikeledi tracking west-southwestward to the southeast of Mayotte Jan. 12 /update 4

Severe Tropical Storm Dikeledi is tracking west-southwestward in the Mozambique Channel to the southeast of Mayotte after passing over far northern Madagascar following landfall between the towns of Antsiranana in Diana Region and Vohemar in Sava Region late Jan. 11. As of 12:00 EAT, the storm's center of circulation was approximately 604 km (375 miles) east of Nacala, Mozambique.

Forecast models indicate the system will remain a severe tropical storm as it passes south of Mayotte Jan. 12 before strengthening a tropical cyclone as it tracks southwestward and passes close to the coast of Nampula Province, Mozambique, Jan. 13. Dikeledi is expected to strengthen further as it turns to track south-southwestward and then south-southeastward over the Mozambique Channel Jan. 14-15, before weakening slightly as it passes close to the southwest coast of Madagascar late Jan. 15-early Jan. 16. The system is expected to weaken further and transition into a post-tropical cyclone as it tracks southeastward away from Madagascar Jan. 16-17. Some uncertainty remains in the track and intensity forecast, and changes may occur in the coming hours and days.

As of Jan. 12, Meteo France Mayotte has issued a red cyclone alert (the second highest level on a four-tier scale). Winds gusting up to 90 kph (56 mph) and rainfall totals of 10-15 cm (4-6 inches) are possible during the passing of the storm. Hundreds of people are being accommodated in 79 emergency shelters established across Mayotte. Dzaoudzi–Pamandzi International Airport (DZA) remains closed due to the storm, and ferry crossings between islands are also suspended. Much of Mayotte is still recovering after the devastating impact of Tropical Cyclone Chido, which struck the territory Dec. 14.

Meteo Madagascar is maintaining yellow cyclone alerts (the middle level on a three-tier scale) for Mahajanga I-II, Mitsinjo, and Soalala districts in Boeny Region and blue post-cyclone alerts for Diana Region, Sava Region, and Analalava, Antsohihy, and Bealanana districts in Sofia region. Authorities have also issued red heavy rainfall warnings for Analjirofo and Atsinanana regions and yellow heavy rainfall warnings for Alotra-Mangoro, Betsiboka, and Melaky regions. Red strong wind warnings are in place for coastal areas between Antsiranana and Toamasina and between Antsiranana and Analalava, and yellow warnings are in place between Analalava and Maintirano. Red heavy swell warnings have been issued between Bobaomby and Mahanoro and from Bobaomby to Maintirano, with yellow heavy swell warnings between Maintirano and Morombe. Officials will likely update or rescind existing advisories as the storm progresses.

Authorities in Madagascar have reported two people are missing in Maroantsetra District in Analjirofo Region after being swept away by floodwaters. Around 700 people have been displaced in Vohemar District in Sava Region following the passing of the storm. More than 150 homes have been flooded and 37 damaged and one road in Vohemar District has been made impassable by flooodwaters. All public transport across the Sava Region and all regional and national buses across the Diana Region have been suspended.

The Mozambique National Institute of Meteorology (INAM) has issued an orange cyclone alert for Namupla Province. Heavy rainfall and strong winds are forecast in the region from Jan. 13, with rainfall totals of 3-5 cm (1.2-2 inches) and winds of around 60 kph (37 mph) possible.

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.