La Niña, or the cooling of sea surface temperatures in the equatorial Pacific and characterized by above-normal rainfall, could last longer than expected, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) bared in its latest climate outlook released on Wednesday, April 27.

“La Niña has slightly strengthened and is likely to continue through June-August 2022 with a 59 percent chance, and with a 50-55 percent chance that the La Niña will continue thereafter,” Senior weather specialist Rusy Abastillas said in the PAGASA’s virtual climate outlook forum.

This means that with the prevalence of La Niña, the likelihood of having above normal rainfall conditions in some areas of the country also increases, she pointed out.

“We have to continuously monitor kasi baka mag-linger pa ito hanggang 2023 (because the La Niña may linger until 2023)” Abastillas added.

In the PAGASA’s advisory issued on April 5, it predicted that the La Niña has a 53 percent chance that it will continue through June-July-August 2022 period and shift to ENSO-neutral conditions, where neither La Niña nor El Niño exists, thereafter.

‘Long-term’ La Niña

PAGASA’s Climate Monitoring and Prediction Section chief Ana Liza Solis said back-to-back La Niña events have occurred in 2007 to 2008, 2008 to 2009, 2010 to 2011, 2011 to 2012, 2016 to 2017, and 2017 to 2018.

However, the latest back-to-back La Niña—2020 to 2021 and 2021 to present—appears that the “second comeback” may be longer than anticipated.

Solis said that this has also happened in 1974 to 1976.

The 1973 to 1974 La Niña returned to ENSO-neutral condition briefly, followed by another La Niña from 1974 to 1976, Solis pointed out.

“Dire-diretso po yun. Hindi man siya tinatawag na triple dip La Niña pero yung pangalawang La Niña ay nagtagal ng halos dalawang taon, from 1974 to 1975, 1975 to 1976. (It happened almost instantaneously. It may not be called a triple dip La Niña but the second La Niña lasted for almost two years, from 1974 to 1975, 1975 to 19760,” she explained.

“Kumbaga nangyari na po siya. Although, during that time, before and after po nun ay merong El Niño and historically base sa nakikita nating isinulat ng ating mga scientists na pinublish nila noong 2018 during that time ay merong mga tropical cyclone rapid intensification na nagaganap (This has already happened. Although, during that time, before and after that there was an El Niño and historically based on what was published by our scientists in 2018, there were tropical cyclone rapid intensification that occurred,” she added.

Solis said extreme weather events, such as heavy rainfall, occurred during the long-term La Niña event.

Rainfall forecast

Based on the PAGASA’s rainfall forecast for May, near normal rainfall conditions are expected over most areas of the country, however, Bataan, Occidental Mindoro, Negros Oriental, and Siquijor are likely to receive above normal rainfall.

By June, near normal rainfall conditions are expected in most parts of the country except for the Cordillera Administrative Region, Region 1, and Cagayan where below normal rainfall conditions are likely.

By July 2022, below normal rainfall conditions are expected in Abra, Benguet, Apayao, Tarlac, Sorsogon, Ilocos Norte, La Union, and Pangasinan, while near normal rainfall conditions are likely over the rest of the country.

By August, near normal rainfall conditions are expected throughout the country except for Pampanga and Tarlac, where below normal rainfall conditions are likely.