Cloudy skies with light to moderate rains and isolated thunderstorms will affect parts of Northern Luzon this weekend due to the prevailing frontal system – the boundary between two different air masses that produces clouds and rain.
The Philippine Atmospheric, Geophysical, and Astronomical Services Administration said Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Batanes, Cagayan, Isabela, Nueva Vizcaya, Quirino, Aurora, Bataan, Bulacan, Nueva Ecija, Pampanga, Tarlac, Zambales, Abra, Apayao, Benguet, Ifugao, Kalinga, and Mountain Province will experience light to moderate rains and isolated thunderstorms.
Partly cloudy to cloudy skies with isolated rain showers or thunderstorms mostly in the afternoon or evening will prevail over Metro Manila and the rest of country.
The frequency of rains and thunderstorms in the afternoon and evening manifests the imminent onset of rainy season later this month or early June, the weather bureau said.
The country is currently experiencing a seasonal climate transition from dry to rainy season.
The transition period is manifested by warm and humid condition associated with frequent rain showers and thunderstorms in the afternoon and early evening. Wind pattern will gradually shift to southwest.
However, warm weather will persist in most parts of the country over the weekend, with the maximum heat index in Metro Manila ranging from 39.4 to 39.9 degrees Celsius until Monday.
It will be hot in Tuguegarao City with maximum heat index between 38.6 and 40.1 degrees Celsius for the next four days.
PAGASA advised the public to observe “extreme caution” if the forecast heat factor is between 32 and 41 degrees Celsius (90-105 degrees Fahrenheit) because heat cramps and heat exhaustion are possible, while continuing activity could result in heat stroke.
Heat index is higher by at least two to three degrees Celsius from the actual air temperature. PAGASA also calls it human discomfort index, which “gives the apparent temperature or what human perceive or feel as the temperature affect their body.”
“High air temperatures and high relative humidity will give high apparent temperatures or indices. Full exposure to sunshine can increase heat index by 90 degrees Celsius,” it said. (Ellalyn V. Ruiz)