PAGASA defends forecasts

PAGASA-DOST MTSAT-EIR Satellite Image for 6 p.m., 25 May 2011.

MANILA, Philippines - Typhoon Chedeng (international codename Songda) has accelerated and is estimated to sweep past the Bicol region and eastern Visayas, weather bureau PAGASA said Wednesday afternoon.

In its 5 p.m. bulletin, PAGASA said Chedeng was last spotted 310 east of Catarman, Northern Samar with maximum sustained winds of 130 kilometers per hour near the center and gusts of up to 160 kph.

It is currently moving northwest at 15 kph, and is estimated to make landfall in the vicinity of Aurora and Isabela at around 2 p.m. Friday.

Chedeng is forecast to be 230 km north of Catarman, or 140 km northeast of Virac, Catanduanes by Thursday afternoon.

Public Storm Warning Signal number 2, where winds 61-100 kph is expected in 24 hours, has been raised over Catanduanes, Sorsogon, Albay, Camarines Norte, Camarines Sur, Samar, Eastern Samar, and Northern Samar.

Meanwhile, Public Storm Warning Signal Number 1, where winds 45-60 kph is expected in 36 hours, has been raised over Marinduque, Masbate (including Ticao and Burias islands), Quezon (including Polilio Island), Aurora, Biliran, and Leyte.

'Residents in low lying and mountainous areas under signals #2 & #1 are alerted against possible flashfloods and landslides. Likewise, those living in coastal areas are alerted against big waves or storm surges generated by this tropical cyclone," the bulletin said.

In addition, the typhoon is expected to enhance the southwest monsoon and will bring rains over other parts of the Visayas and Mindanao.

Landfall in northwest Luzon

Science and Technology Undersecretary Graciano Yumul, in an interview on ANC's Top Story on Wednesday, said that the typhoon is seen to make landfall in Luzon before curving northward.

Yumul said that based on their data, Chedeng is estimated to have rainfall of around 25-50 millimeters per hour.

He said that compared to tropical storm Ondoy (Ketsana) in 2009, Chedeng is "stronger" since the rainfall brought by Ondoy - averaging 56 mm/h - was due to the storm and an intertropical convergence zone, while Chedeng's rainfall is solely due to the typhoon.

However, Yumul said despite packing more rains, Chedeng won't be as devastating, since people who will be affected by the weather disturbance are prepared.

He also said that the strong rains experienced in western Luzon, particularly in Metro Manila, are due to an active intertropical convergence zone (ITCZ), while rains in Bicol and eastern Visayas are due to Chedeng.

He said that the speed and direction of the typhoon is being affected by a High Pressure Area (HPA) near China, and the interaction between the two weather systems will have a significant effect on the path of the typhoon.

Yumul said that if there are significant changes in the direction and strength of the typhoon, they will immediately inform the public about it.

He also addressed the differences between forecasts made by meteorological agencies in neighboring countries like Japan, Taiwan, and Hong Kong. He said the PAGASA is using data from both numerical models and real-time field data, while foreign agencies mostly rely on numerical models and satellite imagery.

"The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 p.m. today (Wednesday)," the agency's 5 p.m. bulletin added.

Evacuation in Bicol

The pre-emptive evacuation of thousands of people living in landslide and flood-prone areas in the Bicol region has started ahead of Chedeng's landfall, a civil defense official said on Wednesday.

Benito Ramos, National Disaster Risk Reduction and Management Council (NDRRMC) executive director and Office of Civil Defense administrator, said government soldiers and civilian volunteers are helping carry out the evacuation of threatened residents in the region.

He said the move is in line with President Benigno Aquino III's directive to aim for zero casualty during a typhoon.

Ramos said the residents in Albay, Sorsogon and Catanduanes were being evacuated using various types of vehicles, including 73 military trucks. He said similar pre-emptive evacuations will be undertaken in the Camarines provinces.

He said residents being evacuated could be "in the thousands." The evacuees will stay either with their relatives or in the evacuation centers.

"The order (to evacuate) is not subject to debate. An order is an order...We are aiming for a zero casualty, that is our mandate," he said, adding that the critical dates are Friday and Saturday.

Ramos said the NDRRMC is closely monitoring Eastern Samar, Southern Tagalog and the Ilocos region.

Armed Forces' chief General Eduardo Oban has ordered military units to pre-position troops in disaster-prone areas to help people if the need arises.

Oban said at least 900 soldiers and military reservists who are helping carry out the Brigada Eskwela program of the Department of Education in Metro Manila are ready to shift to disaster-response mode if necessary.

Stranded travelers

Ramos said that the devastation to be wrought by Chedeng may surpass that of tropical storm "Bebeng," which caused P1.3 billion in damage to agriculture and infrastructure. Bebeng struck the Bicol region and Eastern Visayas a few weeks ago.

He said his assessment of the typhoon's devastation is based on Chedeng's strength, rain density, and projected path. The NDRRMC official added that Chedeng may hit rice granaries in Luzon.

He said at least 533 people have been so far stranded at various ports in the Bicol region and Eastern Samar due to suspension of sea travel.

Ramos said flooding caused by heavy downpour has been also monitored in Zamboanga del Sur and Davao del Norte.

In Cordillera Administrative Region, he said the Ifugao-Hungduan-Benguet boundary road in Ifugao has been closed due to landslides. The Mt. Province-Cagayan via Tabuk-Enrile road has also been closed.

Ramos said the heavy downpour that Metro Manila experienced Tuesday and Wednesday was not caused by Chedeng but by the southwest monsoon. With ANC