The weather in Bobo county

A, the cold front often appears cloudy, windy, rainy and snowy, cooling and other weather, so it is correct;

B, when the warm front crosses the border, it often forms continuous rainy weather, which does not meet the meaning of the question;

C, the weather under the influence of quasi-static front is continuous and rainy, which does not meet the meaning of the question;

D, under the influence of anticyclone, downward flow prevails. In the process of sinking, the temperature rises, the water vapor is not easy to condense, and it is sunny, which does not meet the question.

So choose: a.