MANILA – The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has warned of overcast skies with scattered to widespread rain showers across several regions on Thursday, December 18, 2025, as three weather systems—the shear line, northeast monsoon (amihan), and easterlies—continue to bring cloudy conditions and intermittent downpours. While no tropical cyclones are being monitored, the combined systems could still trigger localized flash floods and landslides in vulnerable areas, especially with saturated soils from recent rains.
PAGASA’s 5 a.m. advisory noted that the shear line (convergence of warm and cool air masses) will dominate eastern sections, while the amihan will enhance rains over northern and central Luzon. The easterlies (warm, moist winds from the Pacific) will add isolated thunderstorms across the Visayas and Mindanao.
Affected Areas and Expected Conditions
- Heavy to Intense Rains (100-200 mm in 24 hours): Eastern Visayas (Northern Samar, Eastern Samar, Samar, Leyte, Biliran), Bicol Region (especially Catanduanes, Camarines Norte/Sur, Albay), and Aurora.
- Moderate Rains (50-100 mm): Cagayan Valley, Cordillera Administrative Region (CAR), Quezon, Marinduque, Romblon, and parts of Central Luzon.
- Light to Moderate Rains: Metro Manila, CALABARZON (Cavite, Laguna, Batangas, Rizal), and the rest of Luzon.
- Scattered Thunderstorms: Visayas and Mindanao (especially afternoon/evening).
No gale warnings are in effect, but moderate to rough seas (2.0-4.0 meters) are expected along eastern and northern seaboards. Small vessels are advised to stay docked.
PAGASA weather specialist Obet Badrina urged caution: “Even light rains can accumulate quickly in low-lying and mountainous areas—monitor rivers and avoid unnecessary travel if heavy downpours hit.”
As Simbang Gabi and holiday preparations continue, this rainy outlook serves as a gentle reminder to pack ponchos and stay updated via PAGASA alerts. The systems pose no major cyclone threat, but the combination of moisture and the amihan ensures a wet start to the week.
Regional Weather Summary (December 18, 2025):
| Region | Conditions | Rainfall Risk |
|---|---|---|
| Eastern Visayas & Bicol | Cloudy; scattered to widespread rains/thunderstorms | High (flash floods/landslides) |
| Cagayan Valley & CAR | Cloudy with moderate rains | Moderate |
| Metro Manila & CALABARZON | Partly cloudy; isolated showers | Low |
| Rest of Luzon | Partly cloudy to cloudy; light rains | Low |
| Visayas & Mindanao | Partly cloudy; localized afternoon thunderstorms | Low |