BEIJING, Feb. 16 (Xinhua) -- Heavy smog that has shrouded northern China for days is likely to clear on Sunday as a new wave of rain and snow hits much of the country from the inland plateau to coastal areas.

In the next three days, precipitation is expected in China's western Qinghai-Tibet Plateau and regions east of it, covering more than half of the country, the National Meteorological Center (NMC) said Sunday.

Snow will fall in the southern part of Tibet Autonomous Region and Qinghai Province, as well as in regions along the middle and upper reaches of the Yellow River from Sunday to Tuesday, with a possibility of heavy snow or blizzards in some areas.

Meanwhile, rain is expected to fall in southern China, the lower reaches of the Yellow River and some southwestern areas.

On Sunday, the NMC reissued a yellow alert for heavy fog covering Beijing, Tianjin, and the provinces of Hebei, Shandong, Henan, Shanxi and Shaanxi, which would gradually clear starting on Sunday afternoon.

China's meteorological alerts are labeled blue, yellow, orange and red in order of increasing severity.