Two weather systems are expected to bring widespread rain across Luzon on Friday, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
The southwesterly windflow will bring scattered rains and thunderstorms to the Ilocos Region, Cordillera Administrative Region, and Central Luzon. Meanwhile, the Cagayan Valley Region will experience similar weather conditions due to the influence of a frontal system.
PAGASA warned that moderate to heavy rains in these areas may cause flash floods or landslides.
The southwesterly windflow is also forecast to cause isolated rain showers or thunderstorms in Metro Manila, Calabarzon, and Mimaropa. Localized thunderstorms will bring similar conditions to the rest of the country.
Moderate winds and moderate sea conditions are expected over the northern and eastern sections of northern Luzon. Light to moderate winds and seas are forecast elsewhere in the country.
As of 2 a.m., PAGASA reported that no low-pressure area is being monitored for potential cyclone development.
In addition to rainfall, the weather bureau also warned of dangerous heat levels. The heat index is forecast to reach 46°C in Infanta, Quezon.
A heat index of 43°C is expected in Tuguegarao City, Baler in Aurora, Dipolog in Zamboanga del Norte, and Surigao City in Surigao del Norte.
Several other areas are expected to experience a heat index of 42°C, including Aparri in Cagayan, ISU Echague in Isabela, Casiguran in Aurora, CLSU Muñoz in Nueva Ecija, Alabat in Quezon, Iloilo City, Dumangas in Iloilo, and Butuan City in Agusan del Norte.
The heat index is a measure of what the temperature feels like to the human body when humidity is factored in. PAGASA classifies values between 42°C and 51°C under the “danger” category, with increased risks of heat cramps, heat exhaustion, or heat stroke after prolonged exposure.