Application of mesoscale model-generated sounding in Beijing local rain storm forecasting

According to the features of the local rainstorm in Beijing, this paper mainly analyzed the features and application of mesoscale model-generated sounding of two cases of local rainstorm in Beijing, also a preliminary discussion of the factors which could result in the disagreement of implication between sounding and rainfall forecast was given. The results show the following: (1) the features of the mesoscale model-generated sounding implying the rainstorm are as follows. The troposphere in lower level contains sufficient moisture to support the deep convections. The stratification curve is parallel to the dry adiabat with ground temperature warmer than 31 ℃, and it is relatively dry and cold above 650 hPa. There is a saturation or quasi-saturation level between the 800-600 hPa in the middle and lower troposphere, which is beneficial for occurrence and development of deep convection. 2) The model-generated soundings can provide a useful implication of the temporal distribution of rainstorm, the characteristics of the rain, and the transition from convectional rain to continuous rain. It is necessary to pay more attention to analyze the model-generated sounding due to the possible disagreement between the rainfall and the sounding. 3) The above conclusions are made based on two cases, and further investigation of more cases is needed.