Philippine Sea: Tropical Storm Ma-on tracking westward in the Philippine Sea early Aug. 22 /update 1

Event

Tropical Storm Ma-on (known in the Philippines as Florita) is tracking westward in the Philippine Sea as of Aug. 22. As of 17:00 PHT, the system's center of circulation was approximately 339 km (211 miles) east-northeast of Manila, Philippines.

Forecast models indicate that the storm will continue strengthening while turning to track northwestwards, making landfall as a tropical storm over Isabela Province, Cagayan Valley Region, Philippines, early Aug. 23. After landfall, Ma-on is likely to weaken slightly as it tracks northwest over Isabela, Cagayan, Apayao, then Ilocos Norte provinces before exiting into the South China Sea late Aug. 23. The system is likely to strengthen further as it tracks northwestward across the South China Sea, making landfall as a tropical storm over central Guangdong Province, China, just west of Macau, the afternoon of Aug. 25. After landfall, the storm is likely to weaken rapidly and dissipate over western Guangxi Province the afternoon of Aug. 26. Some uncertainty remains in the track and intensity forecast. Significant changes could occur in the coming days.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) have warned of light to moderate rain over Cagayan, Isabela, Batanes, Aurora, Ilocos Norte, Ilocos Sur, and La Union provinces through late Aug. 22. Heavy to intense rainfall is forecast over Cordillera Administrative Region and Ilocos Region as well as Cagayan, Isabela, and Batanes Provinces late Aug. 22 through the evening of Aug. 23 while moderate to heavy rains are likely over the rest of Cagayan Valley Region as well as northern Aurora, Zambales, Bataan provinces. Tropical Cyclone Wind Signal (TCWS) 2 is in place over eastern Cagayan, eastern and central Isabela, far northern Aurora, and northeastern Quirino provinces. TCWS 1 is in effect over the rest of northern and central Luzon. Moderate to rough seas of 1.2-3.1 meters (4-10 feet) are likely over the northern and eastern seaboards of Luzon. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

Some classes have been suspended in portions of Albay, Cagayan, and Ilocos Norte provinces in advance of the storm. Further class cancellations are likely as the storm approaches.

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 airports in the affected region and temporary closures of ports are also possible. Raw sewage and other hazardous materials mixed with floodwaters pose 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
Philippine Atmospheric Geophysical and Astronomical Services Administration
China Meteorological Administration
Vietnam National Centre for Hydro-Meteorological Forecasting (NCHMF)