Manila, Feb. 20 -- Most areas in the country are forecast to experience rains caused by three weather systems, the weather bureau said Thursday.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said scattered rains and isolated thunderstorms caused by the shear line are forecast in the Visayas, Mimaropa, Bicol Region, Caraga, Laguna, Rizal, and Quezon.

The shear line is expected to bring heavy to intense rains across Northern Samar and Eastern Samar, and moderate to heavy over Quezon, Camarines Norte, Camarines Sur, Catanduanes, Albay, Sorsogon, Masbate, Samar, Biliran, Leyte, Southern Leyte, Dinagat Islands, and Surigao del Norte.

Rains caused by the northeast monsoon or "amihan" will prevail a...