MANILA - El Niño, a weather pattern associated with reduced rainfall, is now affecting the Philippines, the state meteorology bureau said Wednesday.

PAGASA said climate monitoring and analyses indicate that the unusually warm sea surface which started since November 2018 is expected to become a full-blown El Niño.

"El Niño is expected to be weak and will likely result to below normal rainfall conditions in different parts of the country in the coming months," the weather bureau added.

Dry spell and drought, both "precursors" of El Niño, were observed in several provinces in Luzon and Mindanao from September last year to mid-January 2019, PAGASA climate monitoring chief Analiza Solis earlier said.

The weather bureau defines dry spell as 3 consecutive months of 21-60 percent rainfall reduction, while drought is either a dry spell that extends to 5 months or at least 60 percent rainfall reduction for 3 consecutive months.

El Niño, triggered by periodic warming in the eastern Pacific Ocean, could last for 5 months to 2 years, said Solis. The weather pattern generally results in reduced rainfall, PAGASA said in its website.

El Niño also causes tropical cyclones to become erratic, pushing their track northwards and making them stronger, said the weather agency.

For the complete climate outlook, click this link: Climate Outlook 2019