Gulf of Tonkin: Tropical Storm Sanba tracking north-northeasttward in the Gulf of Tonkin as of late Oct. 19 /update 3

Event

Tropical Storm Sanba is tracking north-northeastward in the Gulf of Tonkin late Oct. 19. As of 19:00 ICT, the system's center of circulation was approximately 322 km (200 miles) east of Hanoi, Vietnam.

Forecast models indicate that the storm will strengthen slightly as it approaches southern Guangxi Province, China, early Oct. 20, before making a sharp u-turn to track southwestward. The system is expected to weaken into a tropical depression as it tracks southwestward and then south-southwestward across the Gulf of Tonkin Oct. 20-22, before dissipating as it approaches the coast of central Vietnam. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

Vietnam's National Center for Hydrometeorological Forecasting (NCHMF) has issued a warning bulletin for the storm system, advising that heavy rainfall is likely in northeastern regions through early Oct. 21. Strong winds are also likely in northern coastal regions, as well as rough seas in the Gulf of Tonkin.

Heavy rainfall in recent days has caused flooding in parts of central Vietnam. The inclement weather has displaced more than 7,600 people in Da Nang and Thua Thien Hue provinces and damaged more than 1,600 homes, predominantly in Da Nang City. Authorities have also reported that 15 fishermen are missing after two vessels capsized off the coast of central Vietnam.

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 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. 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 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 surges. 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.

Resources

Joint Typhoon Warning Center (JTWC)
Vietnam National Center for Hydrometeorological Forecasting (NCHMF)