The whole country will continue to experience isolated to scattered rain showers and thunderstorms in the next 24 hours due to the prevalence of a "monsoon trough."
Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) weather specialist Ariel Rojas on Wednesday, June 9, explained that the monsoon trough is part of the intertropical convergence zone or ITCZ that is connected to the monsoon system or "habagat," which has circulations or low pressure systems.
It is a typical source of tropical cyclones in the Western North Pacific from June to September, he added.
As of Wednesday, Rojas said the monsoon trough was connected to the low pressure areas in mainland Asia.
In the next 24 hours, the monsoon trough will bring scattered rain showers and thunderstorms will prevail over Metro Manila, the rest of Luzon, Visayas, Zamboanga del Norte, Zamboanga del Sur, Zamboanga Sibugay, Basilan, and Tawi-Tawi.
Rojas advised those in these areas to remain vigilant against possible flash floods or landslides due to occasional moderate to at times heavy rains.
Meanwhile, the rest of Mindanao will be partly cloudy to cloudy with isolated rain showers or thunderstorms, but there is also a possibility of flash floods or landslides due to severe thunderstorms in the afternoon or evening.
PAGASA has also monitored a low pressure area (LPA) over the West Philippine Sea or 680 kilometers west of Laoag City at around 3 p.m.
Rojas said the LPA is expected to approach the southern part of China, particularly Hainan Island, and the northern part of Vietnam.
It will likely develop into a tropical cyclone but may move away from the Philippine area of responsibility, he said.