Tourists shield themselves from torrential rain with umbrellas and raincoats as they queue up at Tian'anmen Square in Beijing, July 17, 2015. [Photo/IC]

BEIJING - Heavy rain and thunderstorms are forecast to sweep parts of south and central China, as the country's meteorological authority issued a yellow alert for thunder and lightning in Beijing on Saturday.

China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.

The National Meteorological Center (NMC) issued a blue alert for rainstorms in parts of Guangdong, Hainan, Yunnan and Hebei Provinces from Saturday afternoon to Sunday afternoon.

Precipitation is expected to reach up to 180 mm in central and northern Hainan. In some areas, the rain may be accompanied by thunder, said the NMC.

It warned of rain-triggered disasters, such as floods, landslides and mud flows, in the affected regions.