Changsha weather system

A continuous precipitation often occurs when the quasi-static front crosses the boundary. Examples in China are: plum rains in the middle and lower reaches of the Yangtze River in June, and precipitation formed by quasi-static front in Kunming in autumn and winter, which does not meet the meaning of the question;

B, the winter snowfall in the north is mainly caused by cold front, as long as the cold air mass driven by cold high pressure and Mongolian high pressure is correct;

C, the main reason for controlling the cold air mass in the north in winter is that the Mongolian high is an anticyclone, so it does not meet the meaning of the question;

D, quasi-static front often appears continuous precipitation, and the precipitation intensity is small, which does not meet the meaning of the question.

So choose: B.