Philippine Sea: Tropical Depression 25 is tracking westward in Philippine Sea towards the Luzon Strait early Oct. 21 /update 1

Event

Tropical Depression 25, known in the Philippines as Obet, is tracking westward over the Philippine Sea early Oct. 21. As of 11:00 PHT, the system's center of circulation was approximately 748 km (465 miles) north-northeast of Manila, Philippines. Forecast models indicate that the storm will strengthen into a tropical storm and make a close approach to northern Batanes Province, late Oct. 21. After transiting the Luzon Strait, the system is forecast to enter the South China Sea early Oct. 22 before turning to track southwestwards towards central Vietnam, passing just north of the Paracel Islands early Oct. 25. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of early Oct. 21, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) issued Tropical Cyclone Wind Signal (TCWS) 1 over Batanes and northeastern Cagayan provinces as well as over the Babuyan Islands. PAGASA has also warned of moderate to heavy rainfall over Apayao, Batanes, mainland Cagayan, and northern Ilocos Norte provinces, as well as the Babuyan Islands through early Oct. 22. Light to moderate rain is likely over the rest of northern Luzon. Flooding and rain-induced landslides are possible. Officials will likely update and extend the coverage of the relevant weather alerts over the coming days as the system progresses.

Authorities canceled several flights connecting Manila Ninoy Aquino International Airport (MNL) with Cauayan City Airport (CYZ) and Tuguegarao Airport (TUG) Oct. 20. Flights at Basco Airport (BSO) were also canceled. Further flight cancellations are likely as the storm approaches and conditions deteriorate. Authorities suspended classes in portions of the Cagayan Valley Region Oct. 21 in advance of the storm.

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 typhoon or 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