广西中部一次特大暴雨过程雷达回波特征分析

Analysis on the Radar Echo's Characteristics of a Severe Rainstorm in Central Guangxi

[目的]分析2010年6月发生于广西中部的一次特大暴雨天气过程雷达回波特征。[方法]利用常规观测资料和自动站、多普勒雷达等资料,对2010年5月31日～6月1日发生在广西中部的一次特大暴雨过程进行了分析,重点分析了天气雷达观测资料的特征,试图揭示强降水过程雷达回波特征。[结果]这次特大暴雨过程经历了多单体风暴向MCS的演变过程,超级单体和"列车效应"的存在是特大暴雨产生的主要原因;多单体回波质心在移动过程中沿其移动逆向依次伸展是这次强降水过程得以维持的关键因素;回波平均强度与降水量有较好的对应关系,强回波长时间呈准静止状态是强降水产生的有利条件;在径向速度图上,中尺度辐合线、逆风区以及中气旋的存在是判断强降水产生并维持的重要依据;雷达风廓线能较好地反映各层风的配置状况,是判断高空槽是否过境的有效工具。[结论]该研究为短时、临近天气预报提供参考。

[Objective] The aim was to analyze radar echo characteristic of a heavy rainstorm in central Guangxi in June,2010.[Method] Using conventional observations and automatic stations,Doppler radar and other data,a severe rainstorm in central of Guangxi which occurred on 31 May to 1 June 2010 was analyzed.The characteristics of weather radar data were analyzed to reveal the characteristics of radar echo during the heavy precipitation process.[Result] The heavy rainstorm had gone through many singular wind storms towards MCS variation.The existence of ultra-singular and ＂train effect＂ was the main reason of the heavy rainstorm.The results showed that during the heavy rainfall experienced an evolution process from multi-cell storm to MCS,and found that super cell and the ＂train effect＂ was the major reason which caused this torrential rain.The echo centroid of multi-cell storm stretching along its moving reverse order was the key factor which maintained the heavy rain.Analysis also found that the average echo intensity had a good relationship with rainfall.Strong echoes were in quasi-stationary state for a long time and was favorable heavy rain.In the diameter velocity diagram,mesoscale convergence line,the adverse wind regions and the mid-cyclone were the important basis to determine producing and keeping heavy rainfall.Radar wind profile can reflect the configuration of layers of wind conditions,and it was an effective tool to determine whether the trough was in transit or not.[Conclusion] The study provided reference for the short-term and nowcasting report.