South China Sea: Typhoon Nesat tracking west-northwestward as of Oct. 16 /update 2

Event

Typhoon Nesat (named Neneng in the Philippines) is tracking west-northwestward over the eastern South China Sea Oct. 16, having passed over the Babuyan Islands, Philippines, early Oct. 16. As of 14:00 PHST, the system's center of circulation was approximately 557 km (346 miles) north-northwest of Manila, Philippines.

Forecast models indicate that the system will continue to strengthen as it tracks west-northwestward and the west-southwestward in the eastern South China Sea away from the Philippines Oct. 16-18. The storm is then expected to weaken slightly as it makes a close approach to the north of the Paracel Islands Oct. 18-19. The system is forecast to weaken further and transition into a tropical storm as it turns to track west-northwestward and makes a close approach to Hainan Island, China, Oct. 19-20. Nesat is then likely to weaken into a tropical depression as it approaches northern Vietnam Oct. 21. Some uncertainty remains in the track and intensity forecast, and changes could occur over the next few days.

As of Oct. 16, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) had issued a Tropical Cyclone Wind Signal (TCWS) No. 2 alert (the second lowest level on a five-tier scale) for Batanes, western parts of the Babuyan Islands and northwestern Ilocos Norte. A TCWS No. 1 alert has been issued for parts of western Cagayan, northern Abra, the rest of Ilocos Norte, and northern Ilocos Sur provinces. PAGASA has warned of further moderate-to-heavy rainfall in Batanes, Abra, Benguet, Ilocos Norte, and Ilocos Sur provinces, Oct. 16, as well as light-to-moderate with at times heavy rainfall over the Babuyan Islands, the rest of Ilocos Region, and Cordillera Administrative Region. The heavy downpours could trigger flooding and landslides in parts of the affected areas.

The China Meteorological Administration has issued a yellow typhoon warning (the second lowest level on a four-tier scale), advising that the storm will bring rough seas to southern coastal waters and heavy rainfall to parts of southern Zhejiang and northern Fujian provinces Oct. 16-17. Nesat is also forecast to bring heavy rainfall to parts of Taiwan. As of Oct. 16, the Taiwan Central Weather Bureau has issued an extremely torrential rain advisory (the highest level on a four-tier scale) for mountainous areas of both Taoyuan City and Yilan County and a torrential rain advisory for Keelung North Coast, New Taipei City, and mountainous areas of both Taipei City and Hsinchu County. Extremely heavy rain advisories have been issued for the rest of Taipei City, Taoyuan City, and Yilan County, as well as Hualien County and mountainous areas of Taichung City. Heavy rain advisories have been issued for the rest of Hsinchu County, mountainous areas of Nantou County, mountainous areas of Kaohsiung City, mountainous areas of Pingtung County, Hengchun Peninsula, Taitung County, and Lanyu and Ludao islands,

Officials could update and possibly extend the coverage of weather alerts over the coming days.

Authorities in Cagayan Province have reported that more than 2,500 people in the province were being accommodated in emergency evacuation centers as of midday Oct. 16 and nearly 23,000 people have been affected by the storm. Hundreds of people across other parts of northern Luzon were pre-emptively evacuated ahead of the approach of the storm. One Cebu Pacific flight between Manila and Tuguegarao City has been canceled Oct. 16 due to the storm.

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

Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA)
China Meteorological Administration
Taiwan Central Weather Bureau