Some areas in the country will experience cloudy skies with scattered rain showers and thunderstorms due to the intertropical convergence zone (ITCZ), a rain-inducing weather system that has circulations or low pressure systems, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said on Saturday afternoon, Aug. 21.
In the next 24 hours, the ITCZ will affect Metro Manila, Bulacan, Tarlac, Pampanga, Bataan, Zambales, Aurora, Nueva Ecija, Cavite, Laguna, Batangas, Rizal, Quezon, Oriental Mindoro, Occidental Mindoro, Marinduque, Romblon, Palawan, Aklan, Antique, Iloilo, Guimaras, Negros Occidental, Zamboanga Sibugay, Zamboanga del Norte, Zamboanga del Sur, Basilan, Sulu, Tawi-Tawi, Maguindanao, Lanao del Sur, Cotabato, Sarangani, South Cotabato, and Sultan Kudarat.
Meanwhile, PAGASA said the rest of the country will continue to experience fair weather conditions with partly cloudy to cloudy skies and isolated rain showers or thunderstorms.
PAGASA warned the public against flash floods or landslides that may occur during severe thunderstorms, which are often associated with bursts of heavy rainfall, lightning, thunder, gusty winds, and sometimes hail.
Meanwhile, tropical storm "Isang" (international name "Omais") continued to intensify but has no direct effect on the country's weather.
PAGASA said Isang was packing maximum sustained winds of 85 kilometers per hour (kph) near the center and gustiness of up to 105 kph.
"This tropical storm is forecast to intensify into a severe tropical storm tonight or tomorrow early morning (Aug. 22), after which it is likely to reach its peak intensity. A weakening trend may commence by Monday morning (Aug. 23)," PAGASA said.
As of 4 p.m., the center of Isang was estimated at 585 kilometers east-northeast of Itbayat, Batanes.
"The tropical storm is forecast to move generally northwestward today (Aug. 21) through tomorrow morning (Aug. 22) and turn north-northwestward tomorrow afternoon over the East China Sea. It will then move northward on Monday early morning (Aug. 23) and north-northeastward in the afternoon," PAGASA said.
Isang will likely leave the Philippine area of responsibility on Sunday morning or afternoon.