MANILA, Philippines — Four weather systems would prevail over the entire archipelago within the next 24 hours, the Philippine Atmospheric Geophysical and Astronomical Services Administration (Pagasa) said on Tuesday. Pagasa administrator Nathaniel Servando said that Pagasa has not monitored any weather disturbance or, specifically, a low-pressure area entering the country’s area of responsibility. He said the convergence of hot and cold air—shear line—has been affecting Cagayan, Isabela, and Aurora, bringing cloudy skies with scattered rain showers and isolated thunderstorms. Meanwhile, the intertropical convergence zone (ITCZ)—an imaginary line where winds from the northern and southern hemispheres meet—will likely be over Davao Region, bringing overcast skies with scattered rain showers and thunderstorms, according to Pagasa's early morning weather advisory. Moreover, the northeast monsoon or ‘amihan’ would prevail over the Cordillera Administrative Region and the rest of Cagayan Valley, Ilocos Region, and parts of Central Luzon, where partly cloudy to cloudy skies with isolated light rains would prevail. Pagasa said Metro Manila and the rest of the country would be experiencing partly cloudy to cloudy skies with isolated rain showers or thunderstorms due to the easterlies—winds that bring humid and warm weather.