PAGASA: La Niña possible in last quarter of 2021

There is a 70% to 80% chance of La Niña forming in the fourth quarter of 2021, warned the Philippines’ weather bureau.

This is “based on the latest forecasts by most climate models and experts’ judgments,” said the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) in a statement on Tuesday, September 14.

As a result, PAGASA has shifted from La Niña Watch to La Niña Alert.

“La Niña is characterized by unusually cool ocean surface temperatures in the Central and Eastern Equatorial Pacific,” PAGASA Administrator Vicente Malano explained.

With the threat of La Niña looming, more rain is likely, too.

There is “a higher probability of above-normal rainfall conditions in many areas of the country in the next several months,” PAGASA said.

The rain could be triggered by stronger easterlies or warm winds coming from the Pacific Ocean, the northeast monsoon or hanging amihan which would be enhanced, and tropical cyclones.

So far, the Philippines has had 11 tropical cyclones in 2021. Around 20 tropical cyclones form within or enter the Philippine Area of Responsibility each year.

PAGASA also warned that the eastern parts of the country, “which normally receive more rainfall during the last quarter of the year,” may become even more prone to floods and landslides.

“With this scenario, all concerned agencies are advised to take precautionary measures to mitigate the potential adverse impacts of this looming La Niña,” Malano said.

If La Niña is declared in the fourth quarter of 2021, it could last until the first quarter of 2022.

PAGASA previously said the last La Niña episode in 2020-2021 was weak to moderate. The last strong La Niña was experienced in 2010-2011. – Rappler.com