MANILA, Philippines — Luzon starting another waterlogged week, as the southwest monsoon is forecast to dump more than 200 millimeters of rain over Benguet on Monday, August 10 and keep already saturated areas including Metro Manila under threat of floods and landslides before conditions gradually ease from Tuesday.
Zambales, Bataan and Occidental Mindoro may receive 100 to 200 mm of rain on Monday, PAGASA said in its 5 a.m. advisory.
Another 50 to 100 mm may fall over Metro Manila, Ilocos Norte, Ilocos Sur, La Union, Abra, Pangasinan, Kalinga, Mountain Province, Ifugao, Nueva Vizcaya, Tarlac, Nueva Ecija, Pampanga, Bulacan, Rizal, Cavite, Batangas, Laguna and Oriental Mindoro.
The renewed downpour follows last week’s prolonged wet spell, when Tropical Storm Maymay, internationally known as Kujira, and monsoon-triggered flooding across Metro Manila and several provinces. Four people were killed in landslides in Benguet and Rizal.
PAGASA warned that days of rain have saturated the ground, leaving communities vulnerable even as rainfall totals begin to decline.
“We have been experiencing rain for several days, so the ground is already saturated and the chances of flooding and landslides are high,” weather forecaster Chanel Dominguez said.
Flood risk remains in Metro Manila
With rains forecast to continue, flooding remains a threat in Metro Manila and surrounding provinces. An orange rainfall warning was in effect at 5 a.m. over Zambales, Bataan, Metro Manila, Pampanga, Rizal, Bulacan and portions of Cavite, Batangas and Tarlac, meaning flooding was threatening in affected areas.
PAGASA’s 6 a.m. flood bulletin also warned of continued rain over the Pasig-Marikina-Laguna de Bay river basin through Monday afternoon.
Waterways being monitored include the upper and lower Marikina River, Pasig River and San Juan River, as well as tributaries around Laguna de Bay in Metro Manila, Rizal and Laguna.
The Tullahan River, which runs through parts of Quezon City, Caloocan, Malabon, Navotas and Valenzuela, was also being watched.
La Mesa Dam stood at 79.90 meters as of 5 a.m., just below its 80.15-meter overflow elevation.
Rain seen easing from Tuesday
The monsoon rains are forecast to gradually ease beginning Tuesday, but several already soaked provinces remain at risk.
Benguet, Zambales, Bataan and Occidental Mindoro may still receive 100 to 200 mm on Tuesday, while Ilocos Sur, La Union, Pangasinan, Batangas and Oriental Mindoro may get 50 to 100 mm.
By Wednesday, the heavier rainfall outlook narrows to Zambales, Bataan and Occidental Mindoro, where 50 to 100 mm is forecast.
PAGASA cautioned that rainfall may be heavier over mountainous and elevated terrain and that impacts may be worse in places that have already received significant rain.
A gale warning also remained in effect over parts of the western seaboards of Northern and Central Luzon. Small vessels were advised not to venture into affected waters.
Storm outside PAR
PAGASA is also monitoring a tropical storm internationally named Peilou outside the Philippine area of responsibility.
As of 3 a.m. Monday, Peilou was about 2,515 kilometers east of extreme Northern Luzon, with maximum sustained winds of 65 kph and gusts of up to 80 kph.
It was moving east-southeastward at 25 kph, away from the Philippines.
For now, the southwest monsoon—locally known as habagat—remains the main weather system affecting Luzon and the western section of Visayas, keeping the start of the week wet even as the heaviest rains are forecast to gradually retreat.