Abstract:In this paper, FY 2E satellite data, Doppler radar products and 4Dvar assimilation data, regional automatic station data, conventional meteorological data and NCEP reanalysis data are used to analyze the organizational structure, evolution and formation mechanism of rainstorm cloud clusters over the north Huanghuai Region on 13 August 2010. The results indicate that the cloud clusters developed under the synoptic situation of low vortex and shear. The southwest jet, low vortex shear line and cold air were the main weather systems. The clusters’ ambient characteristics included high instable convective energy, strong low level vertical wind shear and sufficient moisture. MβCSs, which induced heavy rainfall during the early period, had different forming mechanisms. With the development of low vortex, several MβCSs merged into a round MαCS. The force of warm moisture airflow in low level and convergence line on surface were the main mechanism of the round MαCS. γ or β mesoscale cyclone and convergence line created the dynamic triggering effects. Enhancement and extension backward of convergence area led to the self and backward development of MCS. Strong outflow at the back of convective cell during the mature stage caused the cells to break, and convergence of southwest airflow and south airflow on the edge of the cyclone circulation made the combination of convective cells. The linear convective systems that developed during the mature and decline phase of MαCS showed obvious characteristics of heavy rainfall.