BEIJING, Oct. 14 (Xinhua) -- Parts of southern China will be swept by heavy rain from Sunday to Tuesday, while parts of northern China will be shrouded in smog, said the country's national observatory Sunday.

The National Meteorological Center (NMC) forecast heavy rain or rainstorms accompanied by thunder in parts of Guangxi and Guangdong from Sunday evening to Tuesday.

Rainfall could be up to 80 mm per hour in these regions, according to the NMC.

From Sunday evening to Tuesday morning, smog will envelop central and southern parts of north China and northern parts of the Yellow and Huaihe rivers due to a weak cold front.

Conditions for the air to diffuse will gradually improve in most of these regions starting Tuesday, the NMC said.