The Observatory said it will issue the Gale or Storm Signal No 8 between midnight and 2am on Sunday, as Wipha edges closer to the vicinity of the Pearl River Estuary.

Shum Chi-tai, the acting senior scientific officer, said local winds are expected to reach gale to storm force.

"Adverse weather will persist during the day [on Sunday]," he said.

"Depending on the distance between Wipha and Hong Kong, whether Wipha will further intensify into a typhoon and the change in local wind condition, the Observatory will assess the need of issuing higher tropical cyclone warning signals [Sunday] morning.

Shum also said seas would be high with swells, and advised people to stay away from the shoreline and not to engage in water sports.

He added that flooding may occur in low-lying coastal areas.