The state weather bureau formally declares the onset of the Northeast monsoon season or Amihan in the country on Thursday.

The Philippine Atmospheric Geophysical and Astronomical Services Administration (Pagasa) said the onset of Amihan was declared following the observance of the strong to gale-force northeasterly winds that have prevailed over Northern Luzon due to the strengthening of the high pressure system over Siberia for the past several days, and the gradual cooling of the surface air temperature over the northeastern part of Luzon.

"With these developments, the northeast wind flow is expected to gradually become more dominant over Northern Luzon, bringing cold and dry air," it stated.

"Surges of cold temperatures may also be expected in the coming months," it added.

Pagasa also warned that with the ongoing La Nina, "Amihan may be enhanced and trigger floods, flash floods, and rain-induced landslides over susceptible areas."

"Therefore all concerned government agencies and the public are advised to take precautionary measures to mitigate the potential impacts of these events," it noted. Robina Asido/DMS