The current track of Mangkhut is that the typhoon is likely to brush northern Luzon, a less populated part of the largest island in the Philippines, which is home to the capital, Manila.
As the USA east coast braces for Hurricane Florence, an even stronger super typhoon is barreling down on southeast Asia, with Hong Kong and Macau square in its path.
According to the U.N. Global Disaster Alert and Coordination System, the super typhoon could affect as many as 43.4 million people before it fades away.
Weather expert Daniel Wu (吳德榮) told CNA today that Super Typhoon Mangkhut is the strongest storm seen on the surface of the Earth this year, even surpassing Florence, which is a category 4 hurricane, in terms of power.
The storm, named after a fruit in Thailand, is forecast by the USA military's Joint Typhoon Warning Center to bring top winds of 145 knots (268 kilometers per hour) with maximum gusts of 175 knots.
It is now barreling across the Pacific Ocean with wind gusts of more than 178 mph an hour (287 kph).More news: Hurricane Florence prompts mass evacuations
More news: Kingdom Hearts VR to Hit PS4 in 2018 Ahead of Kingdom Hearts
More news: How to watch the keynote and iPhone X reveals
Typhoon Haiyan left more than 7,300 people dead or missing and displaced more than 5 million in the central Philippines in 2013.
"Hong Kong as of the forecast now will be on the right quadrant of the storm with the greatest impacts from wind, rain and storm surge along that coast line", he said.
Classes have also been cancelled in some areas of Luzon in the path of the typhoon. According to HKO, the storm is expected to skirt around 100 to 200 kilometers (62 to 124 miles) south of Hong Kong on Wednesday afternoon, bringing strong winds and rain.
It is due to hit Hong Kong - a densely packed skyscraper city with more than seven million residents.
Mangkhut has been predicted to be the strongest storm to ever hit Hong Kong since records began according to South China Morning Post, and is expected to bring heavy rain and chances of flooding to the harbour city on Sunday.
The observatory said Mangkhut will pack winds of up to 220 kilometres per hour (136 miles per hour) as it passes through Hong Kong.