Research on radar warning indicators of flood induced precipitation processes in Erhai Lake basin

In order to more accurately forecast the flood causing precipitation weather process in Erhai Lake basin, multi-source data such as automatic weather stations, satellites, and radars were used. The radar warning indicators for flood induced precipitation in Erhai Lake basin were obtained through the detailed analysis of radar characteristics of local and regional heavy precipitation processes. On the reflectivity factor map, there are strong echo regions with echo intensity above 45 dBz or stratified mixed precipitation echoes dominated by stratiform cloud echoes, and the strong echo regions maintain for a long time, and bright bands of zero degree layer appear during the precipitation process. The convergence and upwind areas appear on the radial velocity maps with different elevation angles for multiple times. The vertically integrated liquid water content (VIL) shows an obvious increasing trend, with the VIL of multiple volume scans exceeding 15 kg/m² during local heavy rainfall, and ranging from 1 to 5 kg/m² during regional heavy rainfall. The maximum top height of echo can reach 12−15 km during local heavy rainfalls, while the top height of echo in most areas is 5−6 km during regional heavy rainfall, with a maximum of 8−9 km.