Typhoon Tisoy may significantly increase Angat Dam water level —Mang Tani

The water level in Angat Dam may significantly increase as Typhoon Tisoy is expected to bring heavy rains over Luzon, according to GMA resident meteorologist Nathaniel "Mang Tani" Cruz on Monday.

"Kung titingnan natin 'yung ulan na tatama sa Angat Dam, malalakas na ulan 'yan lalo bukas—intense o pwedeng torrential," Mang Tani said in a weather report on GMA News TV's Balitanghali.

"Yun nga lang posibleng hindi mapupuno 'yung Angat Dam dahil dito sa bagyong Tisoy, pero madagdagdagan 'yan siguro. Significant 'yung itatataas niyan, siguro mga tatlo, apat, o limang metro," he added.

According to the Metropolitan Waterworks and Sewerage System, Angat Dam's water level is 189.05 meters, as of December 2.

The normal high water level in the said dam located in Central Luzon is 210 meters.

However, while the typhoon is seen to provide additional water supply, it may also cause flooding in susceptible areas.

"Baha naman ang katumbas niyan sa ilang bahagi ng Central at Southern Luzon," Mang Tani said.

PAGASA said that between Monday and Tuesday afternoon, the Bicol region, Northern Samar, southern Quezon, and Marinduque may experience frequent to continuous heavy to intense rains. Romblon, Mindoro, Samar, Eastern Samar and the rest of Calabarzon, meanwhile, may also expect occasional heavy rains.

Intermittent heavy rains are likely over Metro Manila, Central Luzon, eastern portions of Cagayan and Isabela, and the rest of Eastern Visayas.

The state weather bureau said that Tisoy may make landfall over Catanduanes, Albay, or Sorsogon between Monday night and early Tuesday morning.

According to Mang Tani, Tisoy may weaken after making landfall but there's also a possibility that it will re-intensify as it will still cross other bodies of water.

"Kapag tumama 'yan sa lupa hihina 'yan pero makikita mo may madadaanan uling tubig 'yan sa pagitan ng Bicol at Quezon at muli na naman sa Quezon dadaan sa tubig 'yan, dadaan pa sa Batangas," he said.

PAGASA projects that Tisoy will exit the Philippine Area of Responsibility by Thursday. — Dona Magsino/BM, GMA News