中文摘要：

利用北京逐时降水资料以及雷达组网产品、RPG衍生的风暴跟踪产品和Cell Trend产品，针对北京“6．23”雨强大、局地性明显的暴雨过程进行较为细致的诊断分析。结果表明，雷达监测产品较好地反映出此次过程是由大量中小尺度涡旋构成的对流性系统暴雨，中尺度特征显著。雷达组网产品较好地捕捉了整体降雨系统的演变过程，单站雷达组合反射率、多仰角基本反射率和径向速度揭示了该暴雨系统的多个对流单体结构和更替变化，其剖面刻画了局地对流降雨系统的典型回波特征，伴随强降雨出现了明显的后向干冷空气侵入弱回波区、前向回波悬垂和穹窿，以及倾斜式的低层辐合、高层辐散结构特征。RPG衍生的风暴跟踪产品和Cell Trend产品很好地监测出暴雨过程中小尺度系统的活动信息。其中，中小尺度涡旋的回波顶高和底高、最大回波高度的变化揭示了造成局地降水的对流单体发生发展过程中的强度、结构、内部气流运动变化特征和雨滴活动；液态水含量以及冰雹概率在整个降水过程中一直处于极大值，表明了该系统的强度与降雨雨量、雨强一致。

英文摘要：

Based on the hourly precipitation at 7 stations of Beijing and original data of CINRAD and derived products in Daxing,a heavy rainfall process which was intensive and local obvious and occurred on 23 June 201 1 was analyzed in detail.The results showed that the convective system mingling with many meso-scale and micro-scale vortexes caused the heavy rainfall,and the meso-scale characteristic was obvious.The composite products of CINRAD could clearly capture the whole evolvement process of the weather sys-tem.The composite reflectivity,base reflectivity with multi-elevation angles and radial velocity of CINRAD described the subtle struc-ture of convective cells and their evolution during the heavy rainfall process.The vertical cross section of convection cells depicted clearly the typical echo features of the heavy rainfall including rear inflow weak echo and echo overhang,the low level convergence and the upper level divergence.The storm tracking information and cell trend products derived by RGP monitored perfectly a large quantity of meso-scale vortexes during the heavy rain.The variations of the echo tops,echo bottom and maximum echo height of meso-scale and micro-scale vortexes reflected the changes of the intensity and structure,the air motion and raindrop activities in the occurrence and development of convection cells.The vertical liquid water content （VIL）and probability of hail（POH）were keeping the high val-ue,which was well corresponding to rainfall intensity and precipitation.