South China Sea: Tropical Storm Chaba tracking northwestward in the South China Sea early July 1 /update 1

Event

Tropical Storm Chaba is tracking northwestward over the South China Sea as of early July 1. As of 11:00 CST, the system's center of circulation was approximately 444 km (276 miles) south of Hong Kong.

Forecast models indicate that the storm will strengthen into a typhoon as it generally tracks northwestward across the South China Sea, passing just east of Hainan Island, China, early July 2 before making landfall as a typhoon over China's Guangdong Province the evening of July 2. Following landfall, the storm is forecast to weaken rapidly as it gradually turns to track north across far southwestern Guangdong then southern and central Guanxi provinces before dissipating in the northeastern part of Guanxi Province early July 4. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of early July 1, Chinese authorities have issued a yellow (second-lowest level on a four-tier scale) typhoon warning. Strong winds of 39-74 kph (25-46 mph) are forecast along the coast of Guangdong Province as well as the eastern and southern coasts of Hainan Island while heavy rains are likely over southern Fujian, southern Guangdong, southeastern Guangxi, and Hainan provinces with the heaviest rain of 10-18 cm (4-7 inches) likely in most of Hainan Island and the southern coast of Guangdong Province. Officials in Hong Kong have issued a No. 3 Strong Wind Signal; winds with a sustained speed of 41-62 kph (25-39 mph) are likely to persist.

Vietnamese authorities have warned of strong winds and large waves in the waters from Binh Thuan to Ca Mau provinces. Large waves together with high tides could result in flooding in low-lying areas from Quang Ninh to Ninh Binh provinces. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

Authorities in Hainan Province have closed the Haikou Xiuying, Railway South, and Xinhai ports through at least July 3. China's National Defense General Office has issued a level 4 emergency response (highest level on a four-tier scale) and sent two working groups to southern Guangdong Province to assist and guide typhoon prevention work.

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. 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 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. 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
China Meteorological Administration
Vietnam National Centre for Hydro-Meteorological Forecasting