Philippine authorities on Saturday warned that a powerful typhoon will likely linger over the country for almost three days, bringing prolonged heavy rain, possible floods and sparking storm surges.
Typhoon Koppu, possibly the second most powerful storm to strike the disaster-prone country this year, is expected to make landfall early Sunday and will not leave the archipelago until Tuesday, the government weather station said.
Weather station director Espie Cayanan said the storm, which has sustained winds of 160 kilometres (100 miles) per hour and gusts of 195 kilometres per hour, could strengthen as it gets closer to the country.
Due to its interaction with another nearby weather disturbance, Typhoon Koppu may move slowly across the northern end of the main Philippine island of Luzon, she warned.
"It may be semi-stationary once it hits," Cayanan told reporters.
The typhoon, moving at 10 kilometres per hour, is expected to make landfall in the northeastern province of Aurora before curving north over Luzon and eventually moving out to sea, she added.
Although the storm will not directly hit the capital, Manila, Cayanan warned that its diameter was so huge that even the southern regions were likely to be affected by strong winds and rain.
Areas hit by the typhoon will suffer "heavy to intense rainfall" with possible tsunami-like storm surges in coastal areas.
Civil defence officials warned that waves as high as 14 metres (46 feet) could occur at sea and banned all vessels from sailing in over half the country.
They also warned of possible floods in river basins and urged residents to heed orders to evacuate ahead of any incident.
"If you are told you need to evacuate, then we appeal to you to evacuate," civil defence chief Alexander Pama said.
He also urged the public to cancel any travel plans over the weekend.
Officials said residents in the storm's path were already evacuating coastal and riverside areas although they did not give exact figures.
Special government units are contacting towns that may be vulnerable to the storm to ensure they are prepared for the storm, the officials said.
Philippine President Benigno Aquino previously warned that Typhoon Koppu could be uniquely destructive because it would bring intense rain over a long period of time.
The Philippines is hit by an average of 20 storms each year, many of them deadly.