The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) on Friday officially declared the onset of rainy season even as Typhoon Domeng intensify into a tropical storm.

"The occurrence of widespread rainfall recorded in most PAGASA stations during the past few days due to the southwest monsoon (“Habagat”) confirms the onset of the rainy season over the western part of the country," the state weather agency said in a statement.

It said those areas, including Metro Manila, are the first to experience the rainy season. It will continue to experience scattered to widespread rains and thunderstorms in the coming days.

"However, such rain events may be followed by dry periods (also known as a 'monsoon break') that could last for several days to two weeks," it said.

PAGASA weather specialist Nikos Penarada said in a briefing Domeng was last spotted at 560 km east of Aparri, Cagayan with winds of up to 65 kph and gusts of up to 80 kph.

It is forecast to move north northeast at 19 kph.

It will enhance the southwest monsoon that will bring moderate to heavy monsoon rains over MIMAROPA (Mindoro, Masbate, Romblon and Palawan), CALABARZON (Cavite, Laguna, Batangas, Rizal and Quezon). Bicol region, western Visayas, and western section of Luzon, including Metro Manila.

Domeng is not expected to make landfall in any part of the country. It will leave the Philippine Area of Responsibility on Sunday. Ella Dionisio/DMS