What is the phenomenon that the temperature drops from zero to below zero within 24 hours and the temperature difference exceeds 10 degrees?

Cold wave is a kind of disastrous weather in winter, and people are used to calling it cold wave. The so-called cold wave is a weather process in which cold air from the north invades China on a large scale, resulting in a large-scale sharp cooling and northerly winds. Cold waves generally occur in late autumn, winter and early spring. According to the regulations of China's meteorological department, if the temperature drop caused by cold air intrusion reaches more than 10℃ and the lowest temperature is lower than 5℃ in one day, it is called a cold wave process. It can be seen that not every cold air heading south is called a cold wave.