The Observatory says it will consider issuing the strong wind signal number 3 between 4pm and 7pm on Monday as a severe tropical storm edges closer to the coast of Guangdong.

The weather forecaster issued the standby signal number one on Sunday night.

According to the latest forecast track, Storm Nalgae will edge close to the vicinity of the Pearl River estuary on Wednesday and Thursday.

The Observatory said that under the combined effects of Nalgae and northeast monsoons, local winds will further strengthen tonight and strong winds will prevail offshore with occasional gales on high ground.

At 9am, Nalgae was estimated to be about 710 kilometres south-southeast of Hong Kong.