Pagasa: Cloudy skies, rain likely due to shear line, monsoon Dec 21

Weather satellite image from Pagasa

MANILA, Philippines — The Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said cloudy skies with chances of rain showers are likely to occur in many parts of the country on Saturday due to the shear line and northeast monsoon.

In Saturday morning weathercast, Pagasa expert Grace Castañeda said the shear line, or the area where warm and cold winds meet, is forecast to bring cloudy skies with rain to Southern Luzon, Visayas, and parts of Mindanao.

“Itong mga pag-ulan na ito ay mga moderate to heavy na mga pag-ulan at kung minsan ay mga intense rin sa pag-ulan, lalong-lalo na dito sa area ng Eastern Visayas,” she noted.

(These rains are moderate to heavy and sometimes intense, especially here in the area of Eastern Visayas.)

READ: New LPA seen off Mindanao may become tropical cyclone in 24-48 hrs

Castañeda likewise said that the northeast monsoon, locally termed amihan, is seen to cause cloudy skies with rain in Cagayan Valley, Cordillera Administrative Region, Aurora, Nueva Ecija, Bulacan, and Metro Manila.

“Sa nalalabing bahagi ng Luzon ay mayroon lamang tayong mararanasang mahihinang pag-ulan o pag-ambon, dulot pa rin yan ng amihan,” she added,

(The rest of Luzon will experience light rains, still due to the northeast monsoon.)

Pagasa further reported Saturday it is monitoring a new low-pressure area (LPA) off Mindanao that may develop into a tropical cyclone within 24 to 48 hours.

READ: Pagasa: No cyclone expected to enter PAR until next week

The trough of the new LPA, which was last located 1,575 kilometers west of Mindanao, is anticipated to trigger scattered rainfall over Zamboanga Peninsula, Basilan, Sulu, and Tawi-Tawi.

“Ang nalalabing bahagi ng Mindanao ngayong araw ay mayroon lamang mararanasan na mga isolated na pag-ulan, pagkidlat at pagkulog,” Castañeda added.

(The rest of Mindanao will experience only isolated rain showers and thunderstorms today.)

Although the new LPA may intensify into a tropical cyclone, Pagasa said it is not expected to enter the Philippine area of responsibility (PAR) and may only graze the PAR line, west of Palawan.

On the country’s seaboards, Pagasa raised a gale warning over the northern and eastern coasts of Catanduanes where wave heights of 3.4 to 4.5 meters may occur on Saturday.