Brace for possible flash floods or landslides as rains may affect a large part of the country in the next few days due to the resurgence of the southwest monsoon or "habagat," a weather forecaster said on Monday.
"Sa mga susunod na araw, ang malaking bahagi ng ating bansa ay makakaranas ng epekto ng monsoon trough dahil inaasahan na natin ang muling pag-ihip ng hanging habagat. (In the coming days, a large part of our country will experience the effects of the monsoon trough as we expect the southwesterly winds to blow again," Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) weather specialist Ariel Rojas said.
He said that the part of the intertropical convergence zone (ITCZ) that attaches to the southwest monsoon or habagat is called the monsoon trough.
"Katulad ng ITCZ, pagsasalubong din yan (monsoon trough) ng hangin. Katulad ng ITCZ, ang hangin sa itaas ng monsoon trough ay galing din sa hilagang-silangan sa northern hemisphere pero ang hangin sa ilalim ng monsoon trough ay habagat o galing sa timog-kanluran. Dahil pagsasalubong din yan ng hangin, may nabubuong kaulapan at malalakas na thunderstorms na nagdudulot ng pag ulan. Normal na kapag dumikit ang ITCZ sa habagat ay nagkakaroon ng malalakas na pag-ulan sa malaking bahagi ng bansa at normal yan na occurrence kapag merong habagat. (Like the ITCZ, monsoon trough is also a convergence of winds. Like the ITCZ, the wind above the monsoon trough also comes from the northeast, from the northern hemisphere. But the wind below the monsoon trough is from the southwest or the habagat. Because it is also a convergence of winds, clouds and strong thunderstorms are also formed causing rains. It is normal that when the ITCZ attaches to the habagat, heavy rains in large parts of the country occur. It is a normal occurrence when the southwest monsoon is active," Rojas explained.
He said that Metro Manila, Baguio City, and most of the rest of Luzon will likely experience the effects of a weak southwest monsoon that may bring cloudy skies with scattered rain showers, lightning, and thunder on Tuesday.
By Wednesday until Thursday, Rojas said part of the ITCZ will already attach to the southwest monsoon that becomes the monsoon trough. Scattered rains and thunderstorms will prevail over Metro Manila, Baguio City, and most of Luzon.
The Bicol Region will be partly cloudy on Tuesday but may also experience scattered rains due to the monsoon trough by Wednesday and Thursday.
Rojas said the ITCZ will remain the dominant weather system across Visayas and Mindanao on Tuesday, but by Wednesday and Thursday, the monsoon trough will already prevail over these areas.
"Posible ang mga biglaang pagbaha dahil may inaasahang malalakas na okasyon ng pagbuhos ng ulan. Pati na ang posibleng pagguho ng lupa sa mountainous areas, especially in Visayas and Mindanao. (Sudden floods are possible because of the expected heavy rainfall events. There may also be possible landslides in mountainous areas, especially in Visayas and Mindanao)," he warned.