Numerical Simulations of a Heavy Rainfall Case in South China

Using a double-parameter non-hydrostatic elastic three-dimensional model with detailed microphysicalprocesses, the authors simulate the heavy rainfall event in South China which occurred on 9 June 1998 andlasted for more than 3 hours. This case is a supercell, and the upward and downward drafts interact witheach other, which transfers rich water vapor at the converging position to upper levels, and the two draftstogether maintain the convective course. The vertical heating profiles and contributions to water matterof five kinds of micro-phase processes are revealed quantitatively in the results. Condensation releases themost heat, which is more than that of the absorption by evaporation and melting. The rain particles firstcome 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 remainshigh. The total amount of rain is 32 mm, a value close to the observations of nearby stations.