Hagupit, known locally as Ruby, has gusts of up to 230km/h (143mph) and is due to hit land on Saturday evening.
It is on course for the Eastern and Northern Samar provinces and the city of Tacloban, where thousands were killed by Typhoon Haiyan a year ago.
Local residents, many of them still living in temporary shelters, are moving away from coastal areas.
President Benigno Aquino, who met disaster agency chiefs on Friday afternoon, has ordered food supplies to be sent to affected areas, as well as military troops and police officers to be deployed to prevent looting in the aftermath.
Local media reported Mr Aquino as saying there was "no indication" for now that Hagupit would be as strong as Haiyan.
Haiyan - known as Yolanda in the Philippines - was the most powerful typhoon ever recorded over land. It tore through the central Philippines in November 2013, leaving more than 7,000 dead or missing.
It could bring storm surges up to one storey high, as well as heavy rain and the risk of landslides, officials have warned.
Schools and government offices are closed in some areas and there were long queues at shops and petrol stations as people stocked up on supplies.
'Deja vu' In Tacloban, many people have taken shelter in the sports stadium.
"It's deja vu, but not the same as last year with Haiyan," local resident Mariano Tan Jr told the BBC.
"We're already prepared... we've stored basic commodities - water, rice, beans, fuel. We're also prepared in case of a power cut.
"We intend to stay," he added. "We survived last year, we will do it again tomorrow. We will still stand our ground because no calamities can break us apart."
About 19,000 people from coastal villages are in 26 evacuation centres, Tacloban's disaster office spokesman Ilderando Bernadas told Reuters.
He said that number was expected to double as the authorities began forcing people to evacuate.
Tacloban's Deputy Mayor Jerry Yaokasin told the BBC's Newsday: "We haven't yet fully recovered from last year's super-typhoon Haiyan and here we go again.
"It's like we're seeing a movie, it's like the Groundhog Day.
"And it's stirring up a lot of emotions in our hearts and bringing back so many painful memories of what happened during super typhoon Haiyan."
The Philippine weather authorities said that as of 16:00 local time on Friday (08:00 GMT) Hagupit was 370km (230 miles) east of Eastern Samar and moving at 13km/h, a relatively slow speed.
It has weakened slightly, but still remains powerful, with sustained winds of 195km/h and gusts of up to 230km/h. Up to 35 provinces and municipalities are likely to be affected.
The US Navy's Joint Typhoon Warning Center had classified Hagupit as a super typhoon but downgraded it on Friday morning. It remains the strongest storm to hit the Philippines this year.
Meteorologists had said there was a chance Hagupit could veer north towards Japan and miss the Philippines altogether, but this scenario is increasingly seen as unlikely.
The Philippines gives its own names to typhoons once they move into Philippine waters, rather than using the international storm-naming system.