Pagasa: Storm-enhanced monsoon rains may persist until Thursday

MANILA, Philippines–Monsoon rains enhanced by Tropical Storm “Maring” continued for the fourth day on Tuesday, submerging wide swaths of Luzon in floodwater. The inclement weather is feared to persist until Thursday, state forecasters said.

Total rainfall recorded over the past three days at the Science Garden in Diliman, Quezon City, has reached 300 millimeters, according to the Philippine Atmospheric, Geophysical and Astronomical Services
Administration (Pagasa).

Floodwaters submerged houses in BF Resort Village in Las Pinas City after monsoon rains induced by tropical depression “Maring” caused the water level to rise in Metro Manila and nearby provinces Tuesday, Aug. 20, 2013. It was the second straight day of heavy rain, forcing the suspension of classes and work in government offices. JAIME T. CAMPOS/Contributed photo

The average normal rainfall for the month of August is 504.2 millimeters, meaning the three-day volume of rain from Saturday to Monday is only 200 millimeters short of the monthly average.

Even so, this is still well below the 1,007.4 millimeters of rainfall during last year’s monsoon episode from Aug. 6-8. It also falls far short of the rainfall recorded on Sept. 25, 2009 when Tropical Storm Ondoy dumped 455 millimeters of rains over Metro Manila over a 24-hour period.

(Forecasters consider the readings at Science Garden as most representative of the entire Metro Manila unlike other weather stations as the former is inland and resembles the weather in most parts of the capital.)

But Pagasa forecaster Chris Perez said torrential rains spawned by the enhanced southwest monsoon could last longer than the two previous incidents.

“Thus, in terms of impact, we are still assessing because even though there is lower rainfall, it may have a longer duration. We cannot conclude that this has a lighter or heavier impact,” he said in an interview.

Pagasa issued a red rainfall warning advisory over Metro Manila and surrounding provinces at 7:30 a.m., indicating intense to heavy torrential rains.

It alerted residents to severe flooding in Metro Manila, Rizal, Laguna, Cavite, Bulacan, Pampanga, Tarlac, Zambales and Bataan. It was the second red rainfall warning over Metro Manila since Maring entered the country’s territory on Saturday. The first was issued Sunday evening.

Pagasa’s rainfall warning has three levels: yellow, orange and red, the last serving as the highest level of alert.

On Tuesday, Maring (international name “Trami”) was predicted to move more briskly northward at 19 kilometers per hour, compared to its slow movement hours before due to interaction with a low pressure area, which had since dissipated.

As of midday Tuesday, the eye of the storm was observed at 595 kilometers east northeast of Itbayat, Batanes, packing peak winds of 95 kilometers per hour and gustiness of up to 120 kph, Pagasa said.

Perez said the storm was expected to depart by Thursday morning, by which time it would likely be 560 kilometers northwest of Itbayat, heading for northern Taiwan.

Weather conditions will gradually improve by Friday, he said.

Based on Pagasa’s 24-hour weather outlook, the whole of Luzon and Western Visayas will experience monsoon rains that may trigger flash floods and landslides.

The rest of the Visayas will have cloudy skies with light to moderate rainshowers and thunderstorms, while Mindanao will be partly cloudy to cloudy with isolated rains or thunderstorms, it said.

Moderate to strong winds blowing from the southwest will prevail throughout the archipelago and the coastal waters will be moderate to rough, Pagasa said.