The alert, issued at 10 a.m. Wednesday, forced the cancellation of ferry trips to outlying islands as well as to neighboring Macao and some mainland cities, Xinhua, the state-run Chinese news agency, reported.
The Hong Kong weather observatory said the storm was centered 87 miles south-southwest of the city and was forecast to move west-northwest at 9 miles per hour toward Guangdong province. Chinese officials said the storm was packing gale-force winds.
Morning trading on Hong Kong's stock exchange was delayed by the warning. Temporary shelters have been opened in Hong Kong as a precaution and 38 flights at Hong Kong International Airport were delayed or canceled due to bad weather, Xinhua reported.