URUMQI -- Northwest China's Xinjiang is girding for a strong spell of snowfall and sharp temperature drops by imposing traffic restrictions and putting heating providers on emergency standby.

The region's meteorological authority on Wednesday upgraded its orange alert for a cold wave to red, the highest level in China's four-tier warning system, after predicting that the lowest temperatures in the western and northern parts of Xinjiang would plunge by 16 to 20 degrees Celsius.

Altay prefecture, a renowned ski destination in northern Xinjiang, has recorded moderate to heavy snow since Tuesday evening. The regional capital Urumqi saw snowfall exceeding 12.1 mm between Wednesday evening and Thursday morning.

To minimize traffic disruptions, Urumqi mobilized more than 16,000 sanitation workers and 1,900 snow-cleaning machines before the morning rush hour kicked off on Thursday.

The region has suspended trains on its major railways and imposed traffic restrictions on 84 road sections, among which 26 had resumed traffic as of Thursday morning.

Heating suppliers in Xinjiang also took various precautions and initiated an emergency response to prevent a fall in indoor temperatures.

"We're on a 24-hour emergency standby to timely respond to any heating malfunctions," said Ma Lei with the main heating supply company in the city of Yining.

Xinjiang is the first stop of this round of cold wave, which will bring a widespread drop in temperatures and usher in China's first large-scale snowfall this winter, according to the National Meteorological Center (NMC).

The NMC said the snowfall is set to expand noticeably on Thursday and Friday, with regions including Shaanxi in Northwest China, Inner Mongolia, Shanxi and Hebei in North China, and Central China's Henan, all likely to see heavy snow or even blizzards.

Meteorological experts warn that this cold wave will cover extensive areas and may be accompanied by sharp temperature drops and strong winds. Relevant authorities are urged to take comprehensive preventive measures, while the public is advised to stay warm and exercise caution in regards to traffic safety.