The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said the southwesterly wind flow began affecting parts of Luzon on Thursday, May 29.
Manila Bulletin
Philippines
National
Southwesterly wind flow expected to bring occasional heavy rains to Luzon, PAGASA warns
Philippines
National
Southwesterly wind flow expected to bring occasional heavy rains to Luzon, PAGASA warns
Southwesterly wind flow expected to bring occasional heavy rains to Luzon, PAGASA warns
Published May 29, 2025 09:45 am
At A Glance
- PAGASA weather specialist Benison Estareja explained that the southwesterly wind flow is considered the initial phase of the southwest monsoon, locally known as "habagat."
PAGASA weather specialist Benison Estareja explained that the southwesterly wind flow is considered the initial phase of the southwest monsoon, locally known as “habagat.”
“The nature of the southwesterly wind flow brings light to moderate rains, with occasional heavy showers that may cause flooding and landslides,” he said.
As of Thursday, cloudy skies with scattered rain showers and thunderstorms were already observed in the Ilocos Region, Batanes, Babuyan Islands, Bataan, Zambales, and Palawan.
Estareja added that the southwesterly wind flow is expected to continue affecting the Ilocos Region, Cordillera Administrative Region, Metro Manila, and parts of Central Luzon, Calabarzon, and Mimaropa until Monday, June 2.
Residents in these areas can anticipate occasional heavy rains, which may increase the risk of flooding and landslides, particularly in vulnerable communities.
Onset of rainy season
Because of the shift in wind patterns and the expected increase in rainfall, Estareja pointed out that conditions are becoming favorable for the declaration of the rainy season early next week.
“We can expect the official declaration of the onset of the southwest monsoon or rainy season in the first few days of June,” he said.
PAGASA declares the start of the rainy season when the southwest monsoon becomes the dominant wind pattern and at least 25 mm of rain is recorded for five consecutive days in at least seven monitoring stations in western Luzon
Moreover, the frontal system, or the collision of cold and warm air masses, may bring rains and isolated thunderstorms over Batanes and Cagayan on Friday, continuing into Saturday morning, May 31.
Estareja said PAGASA is closely monitoring the situation and may issue heavy rainfall warnings and other advisories as necessary.
Meanwhile, localized thunderstorms will prevail in other parts of the country, as the easterlies, or winds from the Pacific Ocean, will no longer directly affect the area.