HONG KONG - Hong Kong rushed to prepare for the arrival of Super Typhoon Ragasa on Tuesday, with officials warning of a "serious threat" comparable to some of the most destructive storms in the city's recent history.
Ragasa was generating winds with maximum sustained speeds of 220 kilometres per hour at its centre as it churned across the South China Sea early Tuesday, having earlier lashed parts of the Philippines, according to Hong Kong's weather service.
The finance centre was preparing for extensive disruption and damage, while nearby Chinese tech hub Shenzhen has ordered the evacuation of 400,000 people.
Hong Kong's airport will remain open but there will be "significant disruption to flight operations" from 6pm Tuesday until the next day, the Airport Authority said.
More than 500 Cathay Pacific flights are expected to be cancelled.
Hong Kong Observatory said it would issue its third-highest typhoon warning, T8, at 2.20pm on Tuesday, at which point businesses close up and most transport shuts down.
Residents scrambled to stock up ahead of Ragasa's arrival, leaving supermarket shelves empty of fresh food, vegetables and bread.
School classes will be suspended on Tuesday and Wednesday. The Hong Kong Jockey Club also cancelled Wednesday's horse-racing meet.
Hong Kong's stock exchange changed its rules this year to keep markets open during typhoons, with the operator telling Bloomberg News that it was "closely monitoring" the situation.
Authorities have told residents of low-lying areas to be alert to flooding, while opening 46 temporary shelters.
Ragasa -- named after the Filipino word for rapid motion -- will be closest to Hong Kong and nearby casino hub Macau on Wednesday morning, according to Chinese weather services.