Vietnam: Tropical Storm Sonca makes landfall in south-central Vietnam early Oct. 15 /update 1

Event

Tropical Storm Sonca has made landfall in Quang Ngai Province, Vietnam, early Oct. 15 is tracking westward across the country. As of 01:00, the system's center of circulation was approximately 100 km (61 miles) southeast of Da Nang.

Forecast models indicate that the storm will weaken back into a depression as it tracks westward over south-central Vietnam early Oct. 15, before dissipating as it tracks west-southwestward over southern Laos and northeastern Cambodia Oct. 15-early Oct. 16. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming hours.

As of Oct. 15, the Vietnam Center for Hydrometeorological Forecasting (NCHMF) has issued an emergency storm alert warning of strong winds, rough seas, storm surge, and heavy rainfall over parts of central Vietnam. Forecast models indicate rainfall totals through Oct. 16 of 40-50 cm (16-20 inches) over Quang Tri, Thua Thien Hue, Da Nang, and Quang Nam provinces and 30-40 cm (12-16 inches) over Quang Ngai Province. Rainfall totals of 7-20 cm (3-8 inches) are likely over other parts of central and south-central Vietnam. Strong winds are forecast in coastal provinces from Thua Thien Hue to Binh Dinh and rough seas generating large waves are expected. Storm surge of 0.2-0.4 meters (0.7-1.3 feet) is also possible in these coastal areas. Authorities will likely issue new warnings or update existing advisories in the coming days as the storm progresses.

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.

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 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 and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events.

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
Vietnam Center for Hydrometeorological Forecasting (NCHMF)