The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) on Monday, Dec. 9, said the week will start with rainy conditions due to scattered rains and thunderstorms brought by three weather systems.
PAGASA Weather Specialist Rhea Torres said there are no low-pressure areas (LPAs) or tropical cyclones within the country’s area of responsibility as of Monday, but the shear line, intertropical convergence zone (ITCZ), and northeast will bring cloudy and rainy weather.
Over the next 24 hours, the shear line is expected to cause cloudy skies, scattered rains, and thunderstorms across Bicol Region, Marinduque, Romblon, Oriental Mindoro, Batangas, Laguna, Rizal, Quezon, and Aurora.
The shear line forms where the cold winds from the northeast monsoon (amihan) meet the warm winds from the Pacific Ocean (easterlies), resulting in rainfall.
Torres said the ITCZ may also bring cloudy skies with scattered rains and isolated thunderstorms across Visayas, Mindanao, and Palawan.
The ITCZ is where the winds from the northern and southern hemispheres converge, leading to the formation of rain clouds. It is also a breeding ground for tropical cyclones.
Moreover, cloudy and rainy conditions are expected over Cagayan Valley and Cordillera Administrative Region due to the amihan.
Torres warned that flash floods and landslides could occur in areas affected by the three weather systems, particularly during moderate to heavy rainfall.
Meanwhile, PAGASA said the amihan may have minimal impact on Ilocos Region and the rest of Central Luzon, where only partly cloudy to cloudy skies with isolated light rains will occur.
The rest of the country will experience partly cloudy to cloudy with isolated rain showers due to localized thunderstorms.
The public is advised to remain vigilant for possible flash floods or landslides during severe thunderstorms.