HONG KONG, Aug 22 (Reuters) - Hong Kong's weather observatory said it might issue its third-highest typhoon warning at midnight, with severe tropical storm Hato forecast to veer within 100 km of the city early on Wednesday, disrupting flights and other services.
The city's flagship carrier, Cathay Pacific, said the storm would "severely" impact flight operations, with the majority of flights to and from Hong Kong between 2200-0900 GMT on Tuesday evening and Wednesday to be cancelled.
Other transport services including some ferries are expected to be suspended.
A senior scientific officer with the weather observatory, Queenie Lam, said that as long as tropical cyclone Hato continued on its current track and intensity, the number 8 typhoon signal could be raised before midnight, with the storm expected to pass closest to Hong Kong early on Wednesday.
The No. 8 signal is the third highest tropical cyclone warning signal for Hong Kong, the highest being No. 10.
The observatory said rough seas with swells were expected with maximum sustained wind speeds near Hato's centre of 120 kph.
Financial markets, schools, businesses and non-essential government services close when the signal, No. 8, or above is hoisted.
There will be no trading in Hong Kong's financial markets on Wednesday morning if the typhoon signal remains at 8 or higher at 9 a.m. (0100 GMT). Trading will be suspended for the whole day if the storm signal is still at 8 or higher at noon.
(Reporting by James Pomfret; Editing by Robert Birsel)