Madagascar: Tropical Depression Eloise moving southwestwards toward the Mozambique Channel, Jan. 20. /update 4

Event

Tropical Depression Eloise is currently impacting northern Madagascar, Jan. 20. As of 0900 EAT, the center of circulation was approximately 320 km (200 miles) north of Antananarivo. The latest forecast guidance indicates that the storm will track southwestward through Jan. 20 before entering the Mozambique Channel Jan. 21. The storm will then strengthen and is forecast to move toward the Mozambique coastline Jan. 23 or 24 and possibly impact parts of southern Mozambique, northeastern South Africa, eastern Zimbabwe, and Eswatini in the subsequent days. Some uncertainty remains in the track and intensity forecast, and changes could occur over the coming days.

Government Advisories
As of 0900 EAT Jan. 20, authorities in Madagascar maintain a post-hazard vigilance warning for Sava, Analanjirofo, Bealanana, Befandriana Avaratra, and Mandritsara. Officials have warned of heavy rain over the northwest Jan. 20 which could result in flooding. Travel by sea north of Toamasina, between Cap d'Ambre and Morombe, is not recommended. Mozambique's Instituto Nacional de Meteorologia has not issued any warnings as of yet. Officials in various impacted countries are likely to update or issue new warnings in the coming days.

Hazardous Conditions
The storm will likely bring further heavy rainfall, strong winds, and rough seas to coastal areas in northern Madagascar in the coming hours. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Rain-induced landslides are possible in steeply sloped terrains. Flooding could isolate some communities for several days. Similar impacts are possible in northeastern South Africa, Eswatini, eastern Zimbabwe, and southern and central Mozambique in the coming days.

Prolonged swells and storm surge generated by the system will likely result in coastal flooding as the system tracks over Madagascar. Strong winds are likely. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are likely.

Transport
In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved. If there is severe damage to infrastructure, repair, or reconstruction efforts may exacerbate residual disruptions.

Advice

Activate contingency plans in areas where authorities forecast severe weather conditions. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high 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 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. Keep any necessary medications in a waterproof container.

Plan accordingly for commercial, transport, and logistics disruptions in areas affected by the storm. 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.

Resources

Joint Typhoon Warning Center
Instituto Nacional de Meteorologia (Mozambique)
Meteo Madagascar
South African Weather Service