"There are many rains in the Qingming Festival, and pedestrians on the road want to break their souls" is the scene of Chizhou in Qingming written by Du Mu, a poet in the Tang Dynasty. It reflects the rainfall in eastern and southern China affected by warm front in spring. At this time, it is impossible for tropical cyclones to control Jianghuai and even the northern region. The quasi-static front of Jianghuai region should appear in the middle and late May to the end of June. The precipitation of fast moving cold front is characterized by violent storms, mostly in summer.