South China Sea: Tropical Depression Nesat tracking northwestward as of Oct. 20 /update 6

Event

Tropical Depression Nesat is tracking northwestward over the South China Sea Oct. 20. As of 13:00 ICT, the system's center of circulation was approximately 189 km (117 miles) north of Da Nang, Vietnam.

Forecast models indicate that the system maintain its strength as it tracks west-northwestward then southwestward Oct. 20-early Oct. 21. The storm is expected to make a turn to the south and make landfall over Quang Tri Province in central Vietnam late Oct. 21. The system is expected to dissipate early Oct. 22 after making landfall. Some uncertainty remains in the track and intensity forecast, and changes could occur over the next few days.

As of Oct. 19, Vietnam's National Center for Hydro-Meteorological Forecasting (NCHMF) issued a final storm warning due to the storm weakening. The center has issued a separate warning for heavy rainfall between Quang Binh and Quang Nam provinces. Rainfall totals of 7-12 cm (2.8-4.7 inches) with localized accumulations of over 20 cm (7.9 inches) are expected across the area. Showers may be accompanied by strong wind gusts, lightning, and possible tornadoes. Officials could update and possibly extend the coverage of weather alerts over the coming days.

Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and track inundation.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, evacuations, and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF)