Tropical Depression Pilandok is strengthening the southwest monsoon across the Philippines, prolonging the threat of heavy rainfall, flash flooding and landslides across already saturated areas of Luzon.
PAGASA reported Pilandok over the Philippine Sea on Monday, August 31, with maximum sustained winds of 55 km/h (34 mph) and gusts reaching 70 km/h (43 mph).
Tropical Depression PILANDOK to become a tropical storm within the next 24 hours; to make pass near Kyushu, Japan later this week. ⚠️
— MattWestPacWX (@MattWestPacWX) August 31, 2026
As of 00Z (8 AM, Manila time) August 31, 2026:
JMA: 55 km/h; 1,000 hPa [10-min] (Tropical Depression)
PAGASA: 55 km/h; 1,000 hPa [10-min]… pic.twitter.com/qZhgI7be1y
The tropical depression remained well offshore and was not expected to make landfall in the Philippines. However, its broad circulation is helping reinforce the Habagat, or southwest monsoon, drawing another surge of moisture toward western Luzon.
That indirect influence is important after several days of heavy monsoon rainfall have already produced flooding, landslides and deadly incidents across the island.
Heavy rain continues across Luzon
Yellow rainfall warnings remained active Monday afternoon across parts of Zambales and Tarlac, indicating that flooding could develop or persist in vulnerable communities.
Heavy rainfall was forecast across 18 Luzon provinces as the southwest monsoon continued feeding moisture into the region.
Western sections of Luzon are particularly exposed because southwesterly winds arriving from the South China Sea encounter mountain ranges close to the coast.
TINGNAN: Sinuong ng isang sasakyan ang rumaragasang tubig sa Tokok-Ambalideng, Kibungan, Benguet nitong Linggo, August 30.
— GMA News (@gmanews) August 31, 2026
Pinaaalalahanan ang mga motorista na mag-ingat dahil sa malalakas na agos ng tubig sa lugar dahil sa patuloy na pag-ulang dulot ng Habagat. | via GMA… pic.twitter.com/F4zv4BlmgM
As the moisture-laden air is forced upward by the terrain, clouds and rainfall can intensify. Embedded thunderstorms can then produce short periods of much heavier rain capable of overwhelming drainage systems and rapidly raising smaller rivers.
The latest rain is falling over catchments that have already absorbed several days of precipitation.
This means it may now take substantially less additional rainfall to generate flash flooding or trigger landslides than it would have before the prolonged Habagat episode began.
Pilandok strengthens the Habagat
Although Pilandok is not forecast to directly strike Luzon, tropical cyclones do not need to make landfall to significantly affect weather hundreds of kilometres away.
The depression’s circulation is helping strengthen the pressure pattern driving southwesterly winds across the South China Sea and toward the Philippines.
This creates a broad corridor transporting warm, moisture-rich tropical air toward western Luzon.
WATCH: Road situation along Macaiban Bridge in Santa Maria, Bulacan as of 7:25 a.m. on Monday, Aug. 31, following heavy rains brought by the southwest monsoon that battered parts of Luzon over the weekend. | 🎥: Joanna Trinidad via @CataMahinayINQ pic.twitter.com/ov6ulnhK4a
— Inquirer (@inquirerdotnet) August 30, 2026
Rainbands embedded within that flow can repeatedly cross similar locations, producing prolonged rainfall rather than a single short-lived thunderstorm.
The effect is a familiar feature of the Philippine wet season. Tropical cyclones passing to the east or north of the country can enhance the Habagat and produce significant flooding far from the cyclone’s actual center.
In this case, Pilandok’s indirect influence is overlapping with already saturated ground and elevated waterways, increasing the hydrological risk.
Communities remain vulnerable after earlier flooding
The latest rainfall comes while communities across Central Luzon are still recovering from earlier flooding and landslides associated with the prolonged southwest monsoon.
Roads, agricultural areas and residential communities have been inundated during the broader Habagat episode, while repeated rainfall has kept soils saturated across several provinces.
The greatest concern now is cumulative rainfall.
Even where individual downpours are less intense than those observed earlier in the event, additional precipitation can quickly run off saturated ground and enter rivers and drainage systems.
Mountainous areas face an additional threat from landslides and debris flows, particularly where slopes have already been destabilized by previous rainfall.
Flood threat continues into September
Pilandok is expected to remain offshore as it continues moving across the Philippine Sea, meaning damaging winds associated directly with the tropical depression are not currently the primary threat to Luzon.
Instead, attention remains focused on the enhanced southwest monsoon.
Further rainbands are expected to affect western and northern sections of the island as August gives way to September.
Residents in flood-prone and mountainous areas are being advised to continue monitoring PAGASA rainfall warnings and local evacuation instructions.
For Luzon, Pilandok’s most significant impact may ultimately come not from the tropical depression itself, but from the additional moisture it is helping funnel into an already prolonged and damaging Habagat.
