Numerical simulations of a heavy rainfall case in South China

Using a double-parameter non-hydrostatic elastic three-dimensional model with detailed microphysical processes, the authors simulate the heavy rainfall event in South China which occurred on 9 June 1998 and lasted for more than 3 hours. This case is a supercell, and the upward and downward drafts interact with each other, which transfers rich water vapor at the converging position to upper levels, and the two drafts together maintain the convective course. The vertical heating profiles and contributions to water matter of five kinds of micro-phase processes are revealed quantitatively in the results. Condensation releases the most heat, which is more than that of the absorption by evaporation and melting. The rain particles first come from the autoconversion of cloud particles, the warm-rain process; later from the cold-rain process, the melting of grauple particles. The precipitation intensity reaches 75 mm h(-1) while its efficiency remains high. The total amount of rain is 32 mm, a value close to the observations of nearby stations.