BEIJING?-?China's weather observatory announced a blue alert Wednesday morning for snow storms that will sweep south China in the coming days.

Cold air moving southward will bring heavy snow to some regions along the Yangtze and Huaihe rivers from Wednesday to Saturday, with some parts forecast up to 30 millimeters of snow, the National Meteorological Center (NMC) said.

Snowstorms will also hit southern parts of the southwest autonomous region of Tibet, the NMC forecast.

Affected by the cold spell, central and east China will see strong winds and sharply lower temperatures starting Thursday. In some areas in north China and south of the Yangtze River, temperatures could drop by 14 degrees Celsius.

In China's four-tier color-coded weather warning system, red represents the most severe weather, followed by orange, yellow and blue.