Philippine Weather Update: Habagat Weakens as Rainy Season Progresses

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) reports that the southwest monsoon, locally known as habagat, has temporarily weakened, leading to a reduction in widespread rainfall across the country. While the onset of the rainy season was officially declared in late May, the current atmospheric transition means the Philippines will experience a mix of localized thunderstorms and fair weather periods in the coming days.

Why is the southwest monsoon weakening?

The weakening of the habagat is attributed to the current positioning of high-pressure areas and the interaction with easterlies—warm winds blowing from the Pacific Ocean. According to PAGASA’s daily weather bulletins, the monsoon’s intensity fluctuates based on the strength of low-pressure areas and tropical cyclones within the Philippine Area of Responsibility (PAR). When the monsoon surge subsides, the easterlies often dominate, bringing localized thunderstorms rather than the continuous, heavy rains associated with an active monsoon flow.

What regions face continued rain risks?

Despite the overall weakening trend, PAGASA maintains that specific areas remain vulnerable to heavy downpours, particularly during the afternoon and evening. Forecasts indicate that mountainous and coastal regions in Western Luzon, including Pangasinan, La Union, and Zambales, may still encounter isolated heavy rain. These localized thunderstorms are common during the transition period of the rainy season and can trigger sudden flash floods or landslides in saturated soil conditions. Residents in these areas are advised to monitor local government advisories for potential hazard warnings.

How does the current season compare to El Niño?

The transition to the rainy season follows a prolonged El Niño event that caused significant agricultural damage and water shortages across the Philippines earlier this year. While the state weather bureau has officially declared the start of the rainy season, meteorologists note that the effects of the lingering El Niño are still present in the climate system.

PAGASA has suspended its traditional heat index bulletins, which were a staple of the dry season reporting, to shift focus toward rainfall monitoring and tropical cyclone tracking. This pivot reflects the standard operational change as the country moves from the extreme heat of the summer months into the monsoon cycle.

Key Weather Facts

• Rainy Season Status: Officially declared by PAGASA in late May 2024.
• Current Driver: A shift from active habagat to the influence of easterlies.
• Monitoring: Heat index bulletins are suspended; focus has shifted to flood and storm monitoring.
• Regional Impact: Localized thunderstorms remain the primary threat for Western Luzon.

As the country moves deeper into the second quarter of the year, the stability of the weather remains subject to the development of tropical cyclones. The public is encouraged to rely on official updates from the PAGASA website and official social media channels to ensure they receive verified information regarding potential weather disturbances.