China: Tropical Storm Prapiroon tracking northward over the South China Sea toward Hainan Province late July 21 /update 2

Tropical Storm Prapiroon is tracking northward over the South China Sea toward Hainan Province, China, late July 21. As of 20:00 CST, the system's center of circulation is approximately 348 km (216 miles) northeast of Da Nang, Vietnam.

Forecast models indicate that the weather system will maintain tropical storm strength as it tracks northwestward and makes landfall over Hainan Province during the early hours of July 22. The system is forecast to track over Hainan Province during the morning of July 22 before entering the Gulf of Tonkin in the afternoon. The storm is forecast to weaken into a tropical depression as it tracks north-northwestward across the Gulf of Tonkin through early July 23 before making another landfall over southwestern Guangxi Region during the afternoon July 23. The system is expected to weaken further and dissipate as it tracks northwestward inland over southwestern Guangxi toward the Vietnam border through July 24. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of late July 21, the China Meteorological Administration has issued a yellow typhoon warning (the second lowest level on a four-tier scale); heavy rainfall and strong winds are forecast over Hanain Province, southwestern Guangdong Province, and southern Guangxi Region in the coming hours and days, with rainfall totals of 25-28 cm (10-11 inches) and winds gusting up to 108 kph (67 mph) possible over parts of Hainan Island.

Vietnam's National Centre for Hydro-Meteorological Forecasting (NCHMF) has warned of rainfall totals of 10-20 cm (4-8 inches) with localized higher amounts of over 25 cm (10 inches) over northern regions July 22-24. Strong winds are expected in coastal areas of Quang Ninh Province and rough seas are likely along the Gulf of Tonkin coast.

Authorities will likely issue new alerts or update/rescind existing advisories depending on the progression of the storm system.

Authorities in Guangxi Region have evacuated more than 26,000 tourists from Weizhou Island ahead of the storm's approach, with ferry services to and from the island set to be suspended July 22-23. Ferry services have also been suspended in the Qiongzhou Strait. High-speed rail services have been suspended across Hainan Island and urban rail services have been suspended in the city of Haikou July 21-22.

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.

Inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at airports and temporary port closures 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.