PAGASA: La Niña to bring above-normal rainfall starting October

Above-normal rainfall may be experienced over Metro Manila and other parts of the country in the last three months of the year, according to state weather bureau PAGASA.

PAGASA said this is due to the possible impact of the La Niña phenomenon.

“October-November-December, La Niña will most likely be a category. Dito natin nakikita ‘yung possible impact ng La Niña sa ating rainfall dahil mas mataas na ang probability of having above-normal rainfall conditions over most parts of the country,” PAGASA climate monitoring and prediction section chief Ana Liza Solis during the 173rd Climate Forum.

(La Niña may develop by October, November, or December. We may see the possible impact of La Niña because there is a high probability of having above-normal rainfall conditions in most parts of the country.)

As of June 24, PAGASA predicted that above-normal rainfall conditions, or 146.4% of normal rainfall in October, 149.8% in November, and 163.7% in December, would occur in Metro Manila.

Above-normal rainfall conditions are also possible in Calabarzon and Mimaropa in the October-December period.

Most parts of the Philippines may experience above-normal rainfall in December.

There are four categories of rainfall conditions: way below normal (less than or equal to 40% of average), below-normal (41%–80%), near-normal (81%–120%), and above-normal (more than 120%).

To determine the category, the forecast rainfall is divided by the normal rainfall, then multiplied by 100%.

Earlier, PAGASA said the La Niña phenomenon may be further pushed back toward the end of the year, with a 55% chance it may occur sometime between October and December. It is also expected to last until the first quarter of 2025.

La Niña is characterized by unusually cooler than average sea surface temperatures (SSTs) in the central and eastern equatorial Pacific (CEEP). It is usually associated with above-normal rainfall conditions. --VAL/VBL, GMA Integrated News