MANILA, Philippines (July 21, 2025) — Widespread flooding has once again engulfed portions of Luzon, particularly in Metro Manila and nearby provinces, as an enhanced southwest monsoon—locally known as habagat—continues to drench the region. The persistent rainfall, driven by a combination of regional low pressure systems and tropical cyclones, is contributing to significant disruptions, rising river levels, and saturated ground that poses ongoing risks of landslides and further flooding.
In the capital region, floodwaters swamped low-lying roads and residential areas over the weekend. Rainfall totals were particularly alarming in key observation stations: La Mesa Dam recorded 350 millimeters, while PAGASA’s Science Garden in Quezon City measured 215 millimeters, both within a 24-hour span. Such extreme accumulations underscore the intensity and longevity of the current monsoonal setup.
A Converging Weather Setup
This latest round of monsoonal rainfall is being driven by a complex interaction of atmospheric features across the western Pacific. Foremost among them is Tropical Storm Cristine, also internationally known as Wipha, which has tracked across the South China Sea and made landfall Monday morning in northern Vietnam near the border with Laos. Though the storm’s center has shifted westward, its trailing circulation continues to draw tropical moisture into the Philippines.
Simultaneously, a monsoonal gyre—a broad area of low pressure typically seen in the western Pacific during the peak of rainy season—is developing just northeast of Luzon. This gyre is expected to reinforce the habagat, further enhancing the southwest wind flow responsible for transporting deep moisture inland.
In addition, a new tropical disturbance has emerged east of Guam, and model guidance suggests it may intensify into a tropical storm—or possibly a typhoon—later this week. If this system continues to deepen and move westward, it could extend the current monsoonal surge well into the final days of July.
“This is a conveyor belt of moisture,” said meteorologists monitoring the setup. “Each of these systems is helping to sustain or enhance southwest monsoonal flow. Even as one storm exits the region, another begins to develop—leading to overlapping and compounding rainfall events.”
Impacts on the Ground
In Metro Manila, the impacts were felt sharply through the weekend. Traffic was snarled on major roadways such as EDSA, Commonwealth Avenue, and sections of C-5, where floodwaters pooled and created bottlenecks. In some neighborhoods, residents waded through knee- to waist-deep water. In many areas, water levels were exacerbated not just by rainfall but by inadequate drainage and sewage overflow.
Urban flooding in Metro Manila is frequently intensified by aging infrastructure and the inability of drainage systems to handle torrential rainfall. Experts have also pointed to clogged waterways, unregulated development, and increased urban sprawl as contributing factors.
Upstream, river systems in Central and Northern Luzon are also under pressure, with elevated levels observed in the Pampanga, Agno, and Abra river basins. PAGASA has issued flood advisories for several provinces, including Zambales, Bataan, La Union, and Ilocos Norte, warning of the possibility of flash floods and landslides, particularly in mountainous terrain.
Rainfall Outlook
The rainfall forecast for the next 5 to 7 days remains concerning. According to ECMWF and JMA model projections, Region I and western Central Luzon may receive an additional 200 to 350 millimeters of rainfall, particularly around Subic, Baguio, and Dagupan. Localized totals could be higher where storm bands become stationary or convective activity is enhanced by daytime heating.
Region II is expected to remain relatively drier, though still at risk for passing squalls and afternoon thunderstorms—especially between Thursday and Saturday, when the monsoonal gyre is expected to peak in strength.
Farther south, heavy rainfall may also spread into portions of Mindoro, Palawan, and parts of Calabarzon, particularly along the western slopes.
The cumulative effect of daily rain events on already saturated soil raises the threat of mudslides and road washouts, particularly along mountain passes and coastal routes. Authorities are urging residents in landslide-prone areas to stay alert and follow evacuation advisories if issued.
Surf and Marine Conditions
While inland flooding remains a pressing concern, the same atmospheric setup is also generating long-period southwest swells that are impacting the west-facing coasts of Luzon and even Taiwan’s east coast. Surfers along La Union, Zambales, and Ilocos Norte beaches may see improved wave conditions this week, with swell heights peaking in the 1.5 to 2.5 meter range.
However, beachgoers are advised to use caution. The enhanced southwest monsoon also increases the risk of strong rip currents, rough surf, and coastal inundation, particularly during high tide.
Health and Safety Warnings
Health authorities have issued public advisories warning against wading or swimming in floodwaters, especially in urban areas where the risk of contamination from sewage and sharp debris is high. Over the years, cases of leptospirosis, skin infections, and wound lacerations from submerged metal and glass have increased significantly following flood events.
Social media has been awash with images and videos of residents playing in flooded streets under the familiar slogan “It’s more fun in the Philippines,” but officials are urging caution.
“We know the spirit of resilience is strong, but we urge everyone to stay out of floodwaters whenever possible,” said local health workers. “Infections and injuries are common and easily preventable.”
Prolonged Setup Likely to Continue
Forecasters expect the current weather pattern to persist through at least mid-next week. Until then, daily surges of rain are likely, especially along the West Coast of Luzon, with nighttime convection occasionally carrying over into early morning hours.
The long-range forecast hinges on the evolution of the developing storm east of Guam, which could impact the western Pacific monsoon trough significantly depending on its track and intensity.
Officials are reminding residents to stay up to date with forecasts and warnings issued by PAGASA and local disaster management offices. Flood-prone communities are advised to prepare for potential evacuations and ensure that emergency supplies and communication devices are fully charged and accessible.
Support and Continued Monitoring
Meteorologists from independent platforms such as Western Pacific Weather have also been providing real-time updates via social media and Patreon-supported broadcasts, helping bridge communication gaps and provide context to ongoing developments. These community-driven updates have become a vital tool during peak rainy seasons.
As always, residents are encouraged to monitor official channels and refrain from spreading unverified information online.
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