There is an 80 percent chance that the La Niña phenomenon will affect the country until the first quarter of 2022, according to the Philippine weather bureau Friday.
La Niña is the colder counterpart of El Niño and is part of the larger El Niño–Southern Oscillation (ENSO) climatic cycle.
Philippine Atmospheric, Geophysical, and Astronomical Services Administration weather specialist Benison Estareja said that based on their recently held Climate Forum, the La Niña prevailing in the country is “weak” but it is likely to continue until the first quarter and has a 50 percent chance of returning to neutral thereafter.
“Kapag sinabi natin na La Niña, mas mainit yong karagatan sa atin bansa. Kapag mas mataas yong sea service temperature, mas mataas yong chance na magkakaroon tayo ng mga cloudiness at pagkakaroon ng mga pag-ulan,” he said.
For December, Estareja said rainfall will be “above normal” for the eastern section of Luzon, MIMAROPA including Palawan, Panay, Negros, Cebu, Northern Samar, Zamboanga del Norte, and Bukidnon. For the rest of the country, it will be “near normal”.
He said the triggering factors are the northeast monsoon (amihan), shear line or tail-end of a frontal system, the intertropical convergence zone (ITCZ), and worst case, the low-pressure areas (LPAs) and tropical cyclones.
“Kapag above normal, kung ano yong usual na nararanasan natin na pag-ulan tuwing buwan ng December, ay possible na mas mataas pa o mas higit pa sa normal,” he said.
Estareja added that at least two tropical cyclones can still be expected in December, and zero to one for January, February, and March.
The incoming names of possible tropical cyclones next month are “Odette and Paulo”.
Based on the Climate Division of PAGASA, Estareja said there is a high chance that the tropical cyclones entering the Philippine Area of Responsibility (PAR) will make landfalls.
“Kapag yong entry point natin ay nasa mababang latitude, for example sa may Silangan ng Visayas or Silangan ng Mindanao, mataas yong chance na nagno-northwest o westward yong movement. Maaaring maapektuhan ang ating mga kababayan sa Southern Luzon, sa Visayas, and even sa may Northern Mindanao, and Caraga Region,” he said.
If the entry point is in the south of Luzon, particularly in the north, the odds of making landfall are slim. Instead, they will pass near to the southern tip of Luzon before recurving away from any landmass.