The Philippines may again experience above normal rainfall conditions later this year as the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) sees the possibility of another La Niña event this 2021.
"Based on climate models, although maaga pa, parang nakikita natin na ganun pa rin ang trend na ‘yung last six episodes na back-to-back La Niña still could persist this year. ‘Yun ‘yung minomonitor natin kung humina. (Based on climate models, although early to confirm, we seem to see that the trend of the last six episodes of back-to-back La Niña could still persist this year. That is what we are closely monitoring, if the current event eventually weakens)," PAGASA's Climatology and Prediction Section chief Ana Liza Solis said during its climate outlook forum on Wednesday, Feb. 24.
Solis noted that the last six episodes were back-to-back La Niña, which occurred in 2007-2008 and 2008-2009; 2010-2011 and 2011-2012; and 2016-2017 and 2017-2018.
The current La Niña episode, she said, will likely to continue through March-May and with a rising probability of returning to El Niño–Southern Oscillation (ENSO)-neutral condition in April-June.
Neutral condition means there is neither La Niña nor El Niño.
"Matataas ang rainfall na natanggap natin noong January and February bunsod na rin ng long-term impacts ng La Niña. There is still a high likelihood of above normal rainfall conditions by March, or even April, may nakikita pa rin tayong above normal rainfall although normally ay dry season sa bansa. (The rainfall we received in January and February was high due to the long-term impacts of La Niña. There is still a high likelihood of above normal rainfall conditions by March, or even April we still see above normal rainfall although normally it is already dry season in the country)," Solis explained.
PAGASA defines La Niña as the cool phase of ENSO, which occurs on average every three to four years.
Solis pointed out that the likely persistence of above normal rainfall conditions could lead to potential adverse impacts, such as flooding and landslides in highly vulnerable areas.
Based on the PAGASA's rainfall forecast, Solis said 79 provinces in eastern Luzon, Visayas, and Mindanao may still experience above average rainfall in March.
By April, 59 provinces may experience above average rainfall and 22 provinces with near normal rainfall condition, she added.
"Pagdating ng May, generally ito ‘yung transition from northeast to southwest monsoon, meron diyan mga trade winds na nagko-converge kung saan medyo maulan pa rin both ‘yung western at eastern section natin. (By May, which is generally the transition period from northeast monsoon to southwest monsoon season, there will be convergence of trade winds that will cause slightly rainy condition in both the western and eastern sections of the country)," Solis said.
PAGASA's rainfall forecast shows 55 provinces may experience above average rainfall and 31 provinces with near normal rainfall condition in May.