BEIJING, Nov. 22 -- China's meteorological authorities on Wednesday renewed a yellow alert for a cold wave, forecasting temperature drops and gales in some parts of the country.

From Wednesday to Friday, temperatures are expected to drop by 6 to 10 degrees Celsius in the middle and lower reaches of the Yangtze River and in areas to their north, according to the National Meteorological Center.

Parts of the Inner Mongolia Autonomous Region, Hebei Province and northeast China could see temperatures plunging by up to 20 degrees Celsius from 8 a.m. Wednesday to 8 a.m. Friday, reducing temperatures in some areas to lower than minus 30 degrees Celsius.

Strong winds and gales are forecast to occur together with temperature drops, and the winds will also affect waters off China's eastern and southern coasts from Thursday to Saturday, said the center.

It has advised the public to keep warm and urged measures to protect livestock and crops.

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