Rains may continue over several parts of the country as there is still a high chance of rains in the afternoon or evening caused by localized thunderstorms, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).

In its weather bulletin on Wednesday, May 18, PAGASA weather specialist Grace Castañeda said that despite the hot and humid weather in the morning, several parts of the country will have isolated rain showers or thunderstorms in the afternoon or evening.

The occurrence of thunderstorms suggests that the transition from the dry to wet season in the country has set in. This also means that the official onset of the rainy season will be declared soon.

The onset of the rainy season for areas under Type I climate classification is usually declared between the second half of May and the first half of June.

“Patuloy na monitoring tayo sa mga indicators ukol sa transition mula tag-init papunta sa tag-ulan lalong lalo na sa areas under Climate Type 1 or yung mga areas na nasa kanlurang bahagi ng Luzon kasama na ang Metro Manila (We will continue to monitor the indicators of the transition from dry to rainy season, especially in areas under Climate Type 1 or the areas in the western part of Luzon including Metro Manila),” Castañeda said.

Areas under Type I climate classification have two pronounced seasons—dry from November to April and wet during the rest of the year.

Meanwhile, in the next 24 hours, the frontal system will bring rains over Batanes, Babuyan Islands, and Ilocos Norte.

PAGASA advised those in areas affected by the frontal system to stay vigilant against possible flash floods or landslides because of moderate to heavy rains.

It also warned the public against severe thunderstorms that may cause flash floods or landslides, especially in vulnerable areas.

Severe thunderstorms are often associated with bursts of heavy rainfall, lightning, thunder, gusty winds, and sometimes hail.