铜仁市2020年6月29日特大暴雨雷达资料分析

Analysis of Radar Data of Torrential Rain on June 29,2020 in Tongren City

利用C波段新一代天气雷资料、探空资料、区域自动站降水资料,对铜仁市2020年6月29—30日特大暴雨天气过程进行分析研究。结果表明:此次天气过程为长江流域切变线西段暴雨,主要受500 hPa低槽、700 hPa和850 hPa低涡切变、地面辐合线共同影响,强的低层辐合、高层辐散的高低空配置,以及梵净山地形抬升作用激发此次强降水。暴雨发生前对流有效位能突增,大气中可转换对流有效位能迅速上升,为暴雨提供不稳定能量。雷达回波特征分析表明此次降雨以局地生成回波产生降水为主,层积云混合型降水回波在碧江、江口等上空聚集且稳定少动,呈“准静止状态”,回波后向传播,存在多个回波单体相互合并现象;强降雨时段,≥35 dBz的回波普遍伸展到8 km以上,中低层存在多个强回波中心核;有逆风区存在且长时间维持。

Based on the C-band data of new generation weather thunder,radiosonde data and precipitation data of regional automatic stations in Tongren City,the heavy rainstorm weather process from June 29 to 30,2020 is analyzed and studied.The results show that the weather process is a heavy rain in the western section of the shear line of the Yangtze River Basin,which is mainly affected by the 500 hPa low trough,700 hPa and 850 hPa low vortex shear,and ground convergence line,strong low-level convergence,high-level divergence,high and low altitude,the configuration and topographical uplift of Fanjing Mountain stimulated the heavy precipitation.The convective effective potential energy in the atmosphere increases rapidly before the rainstorm,which provides unstable energy for the rainstorm.The analysis of radar echo characteristics shows that the precipitation is mainly generated by local echo.The mixed precipitation echo of stratocumulus gathers and moves stably over Bijiang and Jiangkou,showing a"quasi static state".The echo propagates backward,and there are multiple echo units merging with each other.During the period of heavy rainfall,the echo of≥35 dBz generally extends to over 8 km,there are several strong echo center nuclei in the middle and low layers,and there are upwind areas existing and maintained for a long time.