A La Niña episode, marked by enhanced rainfall in the Pacific Ocean, is likely to develop in June, the Philippine Atmospheric, Geophysical and Astronomical Services Administration said Thursday.
At a Zoom news conference, Pagasa administrator Dr. Nathaniel Servando said the agency issued a La Niña watch “because of a higher possibility of more than 50 percent that a La Niña will develop in June, but its effects will be felt in the last part of the year.”
The warm phase of the El Niño Southern Oscillation in the tropical Pacific is to “neutralize” also in June, but Servando warned the El Niño’s “strong” impact — marked by drought, dry spells, and dry conditions—will stay until June.
“Because of this, there will be a delay in the onset of the rainy season,” he told reporters.
Meanwhile, Pagasa’s Hydro-Meteorology Division said the water elevation in all major dams, except for Angat Dam that supplies 90 percent of Metro Manila’s potable water, is decreasing every day due to El Niño.
Apart from the reduced amount of rainfall, the weather bureau said water evaporation of dams contributes to the dwindling water supply.
“To emphasize, the rate of evaporation, if the temperature is too high, is (also) a hydrological cycle, a very complex computation,” it cited.
Analiza Solis, Pagasa Climate Monitoring and Prediction chief, said while there is no guarantee, “there is still a probability of 55 percent of a La Niña to develop in the next six months.”
“Historically, if there is a pre-developing La Niña, there will be below-normal rainfall condition, especially on the onset of the rainy season or southwest monsoon,” Solis said.
“Even if we have the La Niña watch, let us concentrate on the strong impact of El Niño,” she stressed.
Should conditions develop with a 70 percent chance of La Niña within
the next two months, the weather bureau would raise the watch status to La Niña Alert, she said.
If indications of La Niña continue in the next five consecutive months with an 80 percent probability, the weather bureau would raise a La Niña advisory, she added.
