The difference of the model predictability between front rainstorm in the YangtzeHuaihe River Basin and warmarea rainstorm in South China is investigated through numerical model sensitivity experiments.The control experiments indicate that the rainstorms in the YangtzeHuaihe River Basin and South China can be reproduced by WRF model.The experiments were designed in which perturbations consist of random errors with Gaussian noise were added to the initial conditions,including temperature and wind fields.The result shows that small errors in initial conditions make the simulation results change a lot after 24 h both for front rainstorm in the YangtzeHuaihe River Basin and warmarea rainstorm in South China,but the forecasting error grows faster in south china than in the YangtzeHuaihe River Basin,which lead to the bigger change in simulation results.Furthermore,we found that the dispersion grows with time,and the magnitude of dispersion in south China grows faster than that in the YangtzeHuaihe River Basin.In addition,the model predictability of warmarea rainstorm in South China is less than that in the front rainstorm in the YangtzeHuaihe River Basin.