The observatory says it will issue the strong wind signal No. 3 between 3pm and 5pm on Thursday, and will consider issuing a higher signal on Friday as Super Typhoon Saola is edging closer to Hong Kong.

It's forecasting the storm to be rather close to the vicinity of the Pearl River Estuary on Friday and Saturday, and the weather will deteriorate, bringing strong winds and heavy squally showers to the territory.

Depending on the intensity of Saola, its distance from the estuary and changes in local winds, the weather forecaster said it will consider issuing a higher signal on Friday.

At 8am, the storm was estimated to be about 440 kilometres east-southeast of Hong Kong and it's forecast to move towards the coast of eastern Guangdong.