Investigation of Mesoscale Convective Cloud Cluster in South China

The statistical characteristics of 176 mesoscale convective cloud clusters in South China, which are classified into three types in terms of their size, are analysed based on the short interval GMS images and conventional data during April－October, 1980－1988. Two composite model charts are presented for their formation and development, and two typical cases are studied. Some conclusions can be drawn as follows: ① Mesoscale convective cloud cluster is a major menmber of severe mesoscale convective systems in South China. ② The convergences of wind and moisture fields in the surface layer and orographic forcing are the trigger mechanism for the genesis of cloud clusters. ③ Low-level jet and monsoon cloud swell are the most important factors for the development of cloud clusters