Philippine Sea: Tropical Depression 07W moving northwest in the South China Sea as of late July 5 /update 1

Event

Tropical Depression 07W (known in the Philippines as Emong) is moving northwestwards through the South China Sea between the Philippines and Taiwan late July 5. As of 17:00 PHT, the system’s center of circulation was approximately 1,014 km (1,877 miles) east-southeast of Hong Kong. The storm is projected to strengthen into a tropical storm late July 5 before weakening into a tropical depression early July 6 as it moves towards the Chinese mainland. The Philippine authorities claim that the storm may make landfall near the Batanes and Babuyan Islands by late July 5. Forecast models indicate the depression will make landfall near Shantou, Guangdong Province, the morning of July 6. The depression will gradually weaken as it moves further inland in China. Significant uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories

As of 17:00 July 5, Philippine officials are warning of moderate to heavy rains over Batanes and Babuyan Islands through at least the morning of July 6. Officials also warn of possible flash flooding and landslides. Taiwan authorities have issued a Strong Wind Advisory for Pingtung County, Hengchun Peninsula, Taitung County, Lanyu and Ludao Islands through July 6. Officials have also issued a Heavy Rain Advisory for Tainan City, Pingtung County, and Hengchun Peninsula through late July 5.

Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days. Weather warnings could remain active even after the storm's immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards; this is especially true in areas previously impacted by earlier tropical systems this season. The possibility of localized evacuations due to Tropical Depression 07W cannot be discounted if weather conditions prove particularly hazardous.

Hazardous Conditions

Tropical Depression 07W will bring heavy rainfall, strong winds, and storm surge across the affected area through at least late July 6. Impacts will likely be felt in much of northern Luzon in the Philippines, across Taiwan, and parts of mainland China's Guangdong, Fujian, and Jiangxi provinces.

Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Rain-induced landslides are possible in steeply sloped terrains. Flooding could isolate some communities for several days. Prolonged swells and storm surge generated by the system will likely result in coastal flooding as the system approaches land. A persistent onshore flow could make it difficult for the surge to recede and water levels to decrease in coastal river catchments.

In addition to the heavy rain, flooding, and storm surge, Tropical Depression 07W could produce damaging wind gusts to areas along its track. Localized power outages due to uprooted trees and toppled utility lines are possible.

Transport

In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions through at least July 6. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.

Health

Stagnant pools of water during and after flooding increase the incidence of insect- and waterborne diseases, such as dengue fever, cholera, and malaria. The threat of these disease outbreaks is usually elevated in low-income or underdeveloped areas of major urban centers due to incomplete or open sewer lines. The latent threat of waterborne contaminants from inundated industrial sites cannot be discounted; 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 all evacuation orders. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high 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 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. Keep any necessary medications in a waterproof container.

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
Philippine Atmospheric Geophysical and Astronomical Services Administration