The prevailing northeast monsoon, or “amihan,” along with the shear line, will continue to affect parts of the Philippines this week, bringing cooler temperatures and scattered rains, Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) Weather Specialist Benison Estareja said on Sunday, Dec. 8.

Estareja said, starting Monday, Dec. 9, the strengthening amihan will bring cooler weather to Northern Luzon, with light to moderate rains expected in Cagayan Valley and Cordillera Administrative Region.

The amihan will likely extend into parts of Central Luzon as well, he added.

Meanwhile, the shear line, where the cold winds from the amihan meet the warm easterlies from the Pacific, will bring widespread rains and thunderstorms over Central Luzon, Southern Luzon, and the Visayas.

This weather system may cause occasional heavy rainfall in Bicol Region, Eastern Samar, Northern Samar, Samar, Quezon, Aurora, Rizal, Oriental Mindoro, Occidental Mindoro, and Laguna.

Estareja warned of possible flooding and landslides in these areas.

From Tuesday to Wednesday, Dec. 10 to 11, he said the shear line will continue to bring scattered rains and thunderstorms over the eastern portions of Northern and Central Luzon, including Isabela, Quirino, Aurora, Nueva Vizcaya, and Quezon.

Cooler weather and light to moderate rains due to the amihan will persist in the rest of Northern Luzon, he added.

Monsoon rains may particularly affect Cagayan, Batanes, Apayao, and Kalinga.

Throughout the week, the rest of the country may experience isolated rain showers or thunderstorms, especially in the eastern sections of Visayas and Mindanao.

Estareja advised the public to remain vigilant for possible flash floods or landslides, particularly in areas susceptible to these hazards.