BEIJING, Feb. 22 (Xinhua) -- China's national observatory on Thursday issued a yellow alert for heavy fog in the central, eastern and southern areas.

Heavy fog will hit parts of Hubei, Anhui, Jiangsu, Hunan, Jiangxi, Zhejiang and Sichuan provinces from Thursday evening to Friday morning, according to the National Meteorological Center (NMC).

In some areas of Hunan, Jiangxi, Zhejiang and Sichuan, visibility may fall below 200 meters.

In the meantime, light to moderate snow or sleet will hit parts of Xinjiang, Jilin, Sichuan, Qinghai and Tibet, while some parts of Hubei and Yunnan will see rain, said the NMC.

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