The Hong Kong Observatory said it may issue the Tropical Cyclone Warning Signal as early as midnight on Saturday.

The forecaster said the decision hinges on how a broad area of low pressure currently affecting the central and northern South China Sea develops.

Located within 800 kilometres of Hong Kong as of noon, this system has the potential to become a tropical cyclone.

The observatory said it will assess the need for a warning signal to be issued based on the storm's intensity and proximity to the territory.

"Under the combined effect of the area of low pressure and the ridge of high pressure over southeastern China, local winds will strengthen. Depending on the local wind change, the observatory will consider issuing the Strong Monsoon Signal," it said.

People should prepare for unsettled weather, as rainbands are currently impacting Guangdong's coastal waters.

Hong Kong can expect squally showers beginning on Sunday, with rainfall anticipated to increase significantly over the following days.