Nock-Ten is expected to be packing winds of 222 kilometres per hour (138 miles per hour) when it makes landfall on Catanduanes, a remote island of 250,000 people, on Sunday, the US Joint Typhoon Warning Center said.
It is then expected to hit the country's main island of Luzon, including the capital Manila, on Monday.
"We issued an advisory to local government units this morning to conduct preemptive evacuations," Rachel Miranda, spokeswoman for the civil defence office in the Bicol region that includes Catanduanes, told AFP.
Bicol, an agricultural region of 5.5 million people, is often the first area to be hit by the 20 or so storms and typhoons that pound the archipelago each year.
The most powerful and deadliest was Haiyan, which left 7,350 people dead or missing and destroyed entire towns in heavily populated areas of the central Philippines in November 2013.
The Philippine weather service warned of potentially deadly two-metre (six-and-a-half-foot) waves along the east coast, as well as landslides and flash floods from heavy rains.
Local broadcaster ABS-CBN showed footage Saturday of long lines of trucks, cars and vehicles stranded at Bicol ports after the coastguard shut down ferry crossings to nearby islands as a precaution.
The action prevented thousands of people from returning to their hometowns for the Christmas weekend, it said.
Cedric Daep, civil defence chief for the Bicol province of Albay, told AFP at least 400,000 people in that region alone needed to be evacuated.
"Our evacuation centres will not be able to accommodate all of them," he said. Others were being asked to stay with relatives or friends.
"We are requesting vehicle support" from other government agencies to move people to safety, Daep added.