Typhoon Linfa, packing maximum wind speeds of up to 130 kilometres (80 miles) per hour near its centre, was around 200 kilometres northeast of Hong Kong by early afternoon Thursday and was set to hit overnight.
The stronger Typhoon Chan-hom, with maximum winds of 140 kilometres per hour, was hurtling towards the northern coast of Taiwan Thursday and was expected to make landfall in eastern China Saturday, near the coastal cities of Wenzhou and Taizhou.
A third typhoon, Nangka, currently in the Pacific Ocean north of Guam, was heading towards the southeastern coast of Japan, according to the Japan Meteorological Agency, but was not due to make landfall in the next five days.
The Hong Kong Observatory was expected to raise its "T8" storm signal -- its third-highest -- mid-afternoon Thursday which would shut down the stock market, schools and businesses.
Kindergartens are already shut and container ports due to close, with the city's airport warning flights could be affected.
"According to the present forecast track, Linfa is expected to come closest to Hong Kong tonight and tomorrow morning and pose a threat to Hong Kong," the observatory said on its website.
Television images showed powerful waves hitting the coast of cities on the eastern coast of Guangdong, a Chinese province, as the storm passed over en route to Hong Kong.
