PAGASA: 'High risk' of storm surge in N. Luzon areas amid Marce

State weather bureau PAGASA warned Thursday that there was a "high risk" of storm surges striking coastal areas in seven provinces in northern Luzon as Typhoon Marce nears landmass, potentially threatening lives in affected communities.

In its 2 p.m. warning on Thursday, PAGASA recommended that residents in the identified low-lying communities to stay away from the coast or beach, cancel all marine activities, and stay informed of latest updates from the weather agency.

"A HIGH risk of storm surge may occur within the next 48-hours. There is a possibility of life-threatening inundation from rising sea water along high waves in the low lying coastal communities," PAGASA said.

The affected areas and the corresponding estimated storm surge heights were as follows:

More than 3.0 meters

• Batanes — Basco, Ivana, Mahatao, Sabtang, and Uyugan
• Cagayan — Abulug, Aparri, Ballesteros, Buguey, Calayan, Claveria, Gonzaga, Pamplona, Sanchez Mira, Santa Ana, Santa Praxedes, and Santa Teresita
• Ilocos Norte — Bacarra, Badoc, Bangui, Burgos, Currimao, Laoag City, Pagudpud
• Paoay, Pasuquin, and Ilocos Norte

In these areas, PAGASA warned of significant damage to communities, coastal/marine infrastructure and disruptions to all marine-related activities, significant erosion to beaches, and possible river flooding due to storm surge.

2.1 to 3.0 meters

• Cagayan - Baggao, Gattaran, Lal-Lo, and Peñablanca
• Ilocos Sur — Cabugao, Caoayan, City Of Candon, City Of Vigan, Magsingal, Narvacan, San Esteban, San Juan (Lapog), San Vicente, Santa, Santa Catalina, Santa Cruz, Santa Lucia, Santa Maria, Santiago, Santo Domingo, Sinait, and Tagudin
• La Union — Bacnotan, Balaoan, Bangar, Luna

Potential impact was placed at moderate to significant damage to communities, coastal/marine infrastructure and disruptions to all marine-related activities, significant erosion to beaches, and possible river flooding due to storm surge.

For areas with 2.1 to over 3.0 meters storm surge, PAGASA said, "Evacuation is advised. All marine activities must be canceled."

1.0 to 2.0 meters

• Isabela — Dinapigue, Divilacan, Maconacon, and Palanan

PAGASA warned of minimal to moderate damage to communities, coastal/marine infrastructures,  and disruptions to all marine-related activities.

"All marine activities must be canceled," PAGASA said.

Daluyong

The weather bureau said the inundation or flood depth due to the storm surge depends on the topography of the affected areas.

Also known as "daluyong ng bagyo," PAGASA defines a storm surge as the "abnormal rise in sea level that occurs during tropical cyclones."

"It is caused by strong winds and low atmospheric pressures produced by tropical cyclones. As the tropical cyclone approaches the coast, strong winds push the ocean water over the low-lying coastal areas, which can lead to flooding. This makes storm surges very dangerous," PAGASA said.

In its 2 p.m. bulletin on Thursday, PAGASA said three areas were placed under Tropical Cyclone Wind Signal (TCWS) No. 4 as Typhoon Marce intensified and moved to the coastal waters of Sta. Ana, Cagayan. — VDV, GMA Integrated News