The storm, which was about 110 miles southeast of Taiwan Saturday morning, was expected to make landfall between Sunday afternoon and Monday morning in southern China's Guangdong Province, China's official Xinhua news service reported.
Weather officials said the storm was moving northwest at 12 mph. It is forecast to bring strong winds to an area east of Taiwan and China's coastal provinces of Guangdong, Zhejiang and Fujian Saturday and Sunday.
Usagi is nearly 700 miles wide, enabling its 139 mph winds to simultaneously strike the Philippines' northern island of Luzon and Taiwan, The New York Times reported.
In the Philippines, the storm knocked out power and caused evacuations and landslides, but no fatalities were immediately reported.
Taiwanese officials have evacuated about 2,000 people from low-lying and mountainous areas on Taiwan in anticipation of flooding and landslides. Taiwan's military has deployed more than 1,600 soldiers to areas considered high risk, and put another 24,000 on standby, the BBC reported.
In China, more than 20,000 fishing boats have been moved to secure locations, while 4,000 people were evacuated along the coast of Fujian Province.
Cathay Pacific Airways and Dragonair canceled flights from Hong Kong as of 6 p.m. Sunday.
Meteorologists say the storm is expected to drop about 39 inches of rain on its way to China, the BBC reported.
The U.S. Navy Joint Typhoon Warning Center clocked Usagi's winds at 150 mph Friday, with 185 mph gusts, the equivalent of a Category 4 hurricane in the Atlantic.
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