China: Tropical Storm Ma-on tracking west-northwestward across South China Sea early Aug. 25 /update 6

Event

Tropical Storm Ma-on (known in the Philippines as Florita) is tracking west-northwestward across the South China Sea as of early Aug. 25. The storm had previously made landfall over Maconacon Town in Isabela Province, Philippines, early Aug. 23 and crossed over northern Luzon. As of approximately 11:00 CST, the storm is approximately 291 km (181 miles) west-southwest of Hong Kong, China.

Forecast models indicate the storm will make landfall as a tropical storm near Zhanjiang in western Guangdong Province, China, the afternoon of Aug. 25. After landfall in Guangdong, the storm is forecast to weaken rapidly as it tracks across southern Guangdong and Guangxi provinces before dissipating over northern Vietnam. Some uncertainty remains in the track and intensity forecast. Significant changes could occur in the coming days.

The China Meteorological Administration has issued an orange (second highest level on a four-tier scale) typhoon warning Aug. 25; heavy rainfall and strong winds are forecast over most of Guangdong, southern Guangxi, and Hainan provinces. The Hong Kong Observatory has also issued a warning for strong storm activity and strong winds through at least early Aug. 25. Flooding in low-lying areas is possible. Authorities are advising people to stay away from the shoreline.

The Vietnam National Centre for Hydro-Meteorological Forecasting (NCHMF) has warned of heavy to very heavy rainfall of 10-20 cm (4-8 inches) over North Vietnam as well as Thanh Hoa Province through Aug. 26. Strong winds are likely over coastal areas of Quang Ninh, Hai Phong, and Lang Son provinces through early Aug. 26. Authorities have warned of possible flash flooding along rivers are other water bodies, landslides on steep terrain, and localized flooding in residential and low-lying areas in the mountainous provinces of North Vietnam.

Hong Kong authorities have closed the Hong Kong-Zhuhai-Macau Bridge to shipping. As of early Aug. 25, Mass Transit Railway (MTR) rail services are gradually resuming and most bus services are normalizing. Ferry services are scheduled to resume the afternoon of Aug. 25. The afternoon trading session at the stock exchange is likely to resume Aug. 25. Around 140 people evacuated to 31 government temporary shelters across Hong Kong. Reports indicate one injury.

China Railway Guangzhou Group suspended or limited the speed of the trains passing through Guangdong Province Aug. 25. Several cities in the province have suspended classes. Shenzhen officials have suspended airport operations at Shenzhen Bao'an International Airport (SZX) 03:00-14:00 Aug. 25. Some rail services will also be disrupted in the city through at least Aug. 26.

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, rendering some bridges or roadways impassable. Flight disruptions at airports in the affected region and temporary port closures are also possible. Raw sewage and other hazardous materials mixed with floodwaters pose a severe 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 (NCHMF)