Philippines: Tropical Depression 1 tracking northwestward over the Visayan Sea May 25 /update 1

Tropical Depression 1 (known locally in the Philippines as Aghon) is tracking northwestward in the Visayan Sea May 25 following landfalls over Homonhon Island late May 24 and near Giporlos Municipality in Eastern Samar Province early May 25, as well as over Masbate Island in Bicol Region May 25. As of 14:00 PHST, the storm's center of circulation was approximately 294 km (183 miles) southeast of Manila.

Forecast models indicate that the system will strengthen into a tropical storm as it tracks northeastward over the Visayan Sea May 25, passing close to Marinquque Island, before making landfall over Quezon Province early May 26. The system is then expected to track north-northwestward over Calabarzon Region before turning to track northeastward and moving out into the Philippine Sea May 26. Once over open water, the system is expected to strengthen into a severe tropical storm as it continues to track northeastward off the east coast of Luzon May 27. The storm will strengthen briefly into a typhoon before weakening back to a severe tropical storm as it continues to track northeastward over the northwestern Philippine Sea May 28-30. The storm's track and intensity forecast remains somewhat uncertain, and changes may occur over the coming hours and days.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has warned of continued heavy rainfall across parts of the central and northern Philippines; rainfall accumulations of 10-20 cm (4-8 inches) are forecast over Quezon, eastern Laguna, eastern Rizal, Marinduque, Romblon, Camarines Norte, Camarines Sur, and Catanduanes provinces late May 25-26 and Quezon, Camarines Norte, Camarines Sur, and Catanduanes provinces late May 26-27. Tropical Cyclone Wind Signal 1 is in place across eastern Quirino, eastern Nueva Vizcaya, Bulacan, eastern Nueva Ecija, eastern Pampanga, Aurora, Quezon, Metro Manila, eastern Cavite, Laguna, Rizal, eastern Batangas, Marinduque, northeastern Oriental Mindoro, eastern Occidental Mindoro, northern Masbate, Romblon, Camarines Norte, Camarines Sur, Catanduanes, Albay, and Sorsogon provinces.

Several domestic flights connecting Manila with Calbayog, Naga, Romblon, Siargao, Surigao, Tacloban, and Virac have been canceled May 25 due to the adverse weather; further flight disruptions are possible over the coming hours. The Philippine Ports Authority (PPA) has advised against non-essential maritime travel during the storm. The Philippine Coast Guard (PCG) suspended sea travel for all vessels in Quezon, Marinduque, and Romblon provinces May 25. Several ferry services have been suspended, including those connecting Masbate City with Albay, Cebu, and Samar provinces have been canceled. As of early May 25, more than 1,250 passengers in Eastern Visayas Region and more than 800 in Bicol Region were stranded at ports due to the adverse weather. Authorities have warned that more than 1,100 villages from 52 cities and municipalities in Bicol Region are under moderate to very high threats of landslides. Local officials have evacuated an unconfirmed number of residents from high-risk areas in the Pasacao area due to the risk of flooding, landslides, and storm surge.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. 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 regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.