MANILA, Philippines – Three weather systems are affecting parts of Luzon on All Saints’ Day, Wednesday, November 1.

One is the low pressure area (LPA) that the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) has been monitoring. It was already over the coastal waters of Caramoran, Catanduanes, as of 3 am on Wednesday.

The shear line – the point where cold air from the northeast monsoon or amihan converges with warm air from the Pacific Ocean – and the northeast monsoon itself are also affecting some areas.

Due to the combined effects of the LPA and the shear line, scattered rain showers and thunderstorms are expected in Metro Manila, Calabarzon, mainland Cagayan, Isabela, Aurora, Bulacan, Marinduque, and Camarines Norte.

The northeast monsoon will also trigger rain in the rest of Cagayan Valley, the Cordillera Administrative Region, and Nueva Ecija, as well as isolated light rain in the Ilocos Region and the rest of Central Luzon.

The rest of Mimaropa, the rest of Bicol, the Visayas, and Mindanao will have generally fair weather, though there may be isolated rain showers or thunderstorms.

Flash floods and landslides are possible during periods of moderate to heavy rain or severe thunderstorms.

PAGASA Weather Specialist Obet Badrina said the LPA may dissipate on All Saints’ Day. It is less likely to develop into a tropical cyclone.

The weather bureau estimated that one or two tropical cyclones could enter or form within the Philippine Area of Responsibility in November. – Rappler.com