At 8pm, Ma-on was centred about 470 kilometres east-southeast of Dongsha. It is forecast to move northwest or west-northwest at about 22 kilometres per hour across the northeastern part of the South China Sea. Ma-on will edge closer to the coast of Guangdong progressively.

The weather watchdog said local weather would deteriorate significantly, and winds would strengthen gradually on Wednesday night. Winds will significantly strengthen further on Thursday morning. There will be heavy squally showers, very rough to high seas and swells.

Under the influence of storm surges, low-lying areas may be flooding or have backflow of seawater.

Separately, long queues were seen at supermarkets across the city as citizens to stock up on food and supplies before Ma-on hits. Some said they had to wait about 30 minutes before checking out.

Citizens rushed to supermarkets and wet markets to stock up on vegetables, meat, instant noodles, luncheon meat and canning foods – traditional items reserved for typhoons. Some supermarkets are sold out of fresh vegetables and bread in the evening.