The tropical cyclone outside the Philippine Area of Responsibility (PAR) is expected to enter either by Wednesday night or Thursday, the weather bureau said.
The tropical depression, last spotted 1,530 km. east of extreme northern Luzon, is also forecast to reach the tropical storm category within 36 hours.
Once it enters PAR, it will be given the local name, “Inday”.
A steady intensification is also possible as the tropical cyclone moves over the Philippine Sea, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said.
The tropical cyclone, PAGASA said, is unlikely to bring heavy rainfall and severe winds.
However, it may cause moderate to rough seas over the seaboards of extreme northern Luzon during the weekend.
Meanwhile, scattered rain showers and thunderstorms are forecast to prevail over Palawan, Western Visayas, Zamboanga Peninsula, Basilan, Sulu, and Tawi-Tawi on Wednesday due to the Intertropical Convergence Zone (ITCZ) affecting Palawan and Mindanao.
Flash floods or landslides are possible in these areas due to moderate to at times heavy rains.
The rest of the country will experience isolated rain showers caused by localized thunderstorms.
Light to moderate winds and slight to moderate seas will prevail over the entire archipelago. (PNA)