A low pressure area (LPA) being monitored outside the Philippine Area of Responsibility (PAR) has a high chance of developing into a tropical depression within the next 24 hours, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said Saturday.

As of 2 a.m. on Sept. 12, PAGASA identified the system as LPA 09b and said it was being monitored outside the PAR.

Another LPA, identified as LPA 09c, was also being monitored outside the PAR but is unlikely to develop into a tropical depression within the next 24 hours.

Meanwhile, the trough of an LPA is affecting the western section of Northern Luzon, while the southwest monsoon, or habagat, is affecting Central and Southern Luzon.

Ilocos Region, the Cordillera Administrative Region, Isabela, Quirino and Nueva Vizcaya are expected to experience cloudy skies with scattered rains and thunderstorms due to the LPA's trough.

Moderate to heavy rains in these areas may trigger flash floods and landslides.

Metro Manila, Central Luzon, CALABARZON, MIMAROPA and the Bicol Region will also have cloudy skies with scattered rains and thunderstorms due to the southwest monsoon, with possible flash floods and landslides from moderate to at times heavy rains.

The rest of the country will experience partly cloudy to cloudy skies with isolated rain showers or thunderstorms due to localized thunderstorms.

PAGASA warned that severe thunderstorms may also cause flash floods or landslides.

The public is urged to remain alert and follow updates and advisories from DOST-PAGASA.