The diurnal variation of precipitation is one of the most pronounced features that contributes greatly to the weather and climate, which is mainly affected by the large-scale circulation and regional forcing (Dai, 2001). The diurnal variation of precipitation is closely related to the topography, cloud processes, the evolution of convection, radiative transport, the diurnal cycle of atmospheric boundary layer. Therefore, the ability to correctly simulate the diurnal variation of precipitation is an important test for global and regional models (Arakawa &