The Observatory on Sunday said that the Standby Signal No. 1 would remain in force until at least 8pm, as a tropical depression keeps its distance from Hong Kong.

Forecasters said the storm was expected to stay some 600 kilometres away from the SAR, and therefore the standby signal would remain in force.

"The need for issuance of the Strong Wind Signal, No. 3 thereafter depends on the distance between its associated strong winds and the Pearl River Estuary, and the change in local winds," the Observatory said in a statement.

Forecasters warned that local winds are expected to be occasionally strong offshore and on high ground, due to the combined effect of the tropical depression and the ridge of high pressure over southeastern China.

They also expected squally showers and thunderstorms to affect Hong Kong, as seas will be rough with swells.

The Observatory issued the standby signal at 10.20pm on Saturday.