Typhoon Koppu grew stronger but was moving slower towards the north-eastern Philippines as the government urged local authorities to issue forced evacuations of residents in flood-prone areas.
Local officials have been advised to conduct the “forced evacuation” of communities historically hit by flash floods and landslides, as well as coastal villages at risk from destructive storm surges that could reach as high as three metres, civil defence chief Alexander Pama said.
“The situation is critical because the winds are getting stronger and it will get stronger as (Koppu) moves closer,” he said.
Regional civil defence chief Norma Talosig said villagers have been voluntarily moving to safer ground or emergency shelters since early Saturday. He could not immediately give the number of evacuees.
Heavy rains are expected to inundate many areas on the main northern island of Luzon even before the typhoon makes landfall early on Sunday, acting weather bureau chief Esperanza Cayanan said.
Ms Cayanan said another typhoon further east and a high pressure area north of the country would hold Koppu in a “semi-stationary” position and shroud most of Luzon with an enormous band of thick rain clouds.
“We are looking at the possible worst scenario, not to scare but to allow us to prepare,” Ms Cayanan said. “If it stays 24 hours ... and the downpour is sustained, we will surely have floods and landslides.”
She said the typhoon’s cloud band was about 600km across, unleashing the most intense rain close to the centre.
By 6pm on Saturday, the typhoon was about 200km east of Aurora province, where Koppu is predicted to make landfall. It was packing sustained winds of 175km/h, and gusts of up to210km/h. Forecasters said it could grow stronger before it hits land.
AccuWeather said on Saturday the combination of a typhoon’s slow movement and its powerful winds “could spell a disastrous situation for residents and communities in its path”.
President Benigno Aquino appeared on Friday on national television to warn Filipinos about the typhoon and appealed for co-operation to prevent casualties.
It was the first time Mr Aquino had personally issued a storm warning on television since super Typhoon Haiyan barrelled through the central Philippines in November 2013, leaving more than 7,300 dead or missing.
Mr Aquino said an estimated 1.5 million families, or about 7.5 million people, would need relief assistance.
Metropolitan Manila, the sprawling Philippine capital of 12 million, about 145km south east of Aurora, will be spared from the brunt of the typhoon but it is expected to be drenched with intense rain starting late on Saturday, forecaster Adzar Aurelio said.
Koppu is likely to be equivalent to a Category 3 or 4 hurricane, which could cause devastating to catastrophic damage, according to AccuWeather meteorologist Adam Douty.
vere and life-threatening flooding and mudslides”.
Koppu will be the 12th storm to hit the Philippines this year. An average of 20 storms pummel the country annually.