多普勒雷达产品在2次短时强降水过程中的对比分析

Comparison of Two Short-time Heavy Precipitation Processes from Doppler Weather Radar Products

为了提高荆州地区强对流天气的预报预警能力,提升气象服务农业生产水平,利用2015年荆州多普勒雷达资料,对比分析发生于2015年5月15日和2015年6月1日的2次短时强降水过程。结果发现:(1)2次过程的雷达回波最大反射率强度均在50 d Bz以上,并且比较稳定,回波移动过程中均产生了"列车效应";(2)2次过程均出现中尺度辐合,速度图上中尺度辐合区与强回波位置一致;(3)2次过程中的风暴云底高度大部分时间在2~3 km,云顶高度在12 km附近。风暴生成前期均存在明显的VIL跃增和回波顶高跃增现象,VIL跃增量分别为10、20 kg/m2,顶高跃增为3 km和9 km;(4)风暴发展阶段垂直积分液态含水量均比较稳定,分别为40~50 kg/m2和30~40 kg/m2。回波质心高度和最大反射率高度除6月1日出现下沉以外,其余大部时间2次过程回波质心高度均在4~5 km,最大反射率高度在3~6 km;(5)经过风暴追踪等信息的综合分析推断,6月1日可能还出现下击暴流。

To improve the forecasting and early-warming ability of severe convection weather in Jingzhou, and enhance meteorological service for agricultural production, the authors analyzed two short-time strong precipitation processes occurred on May 15 and June 1, 2015, by using Doppler radar data in Jingzhou. The results showed that： （1） the maximum radar echo intensity of these two processes were more than 50 dBz and stable, and ＂train effect＂ occurred during the moving of radar echo; （2） mesoscale convergence occurred in both processes, and the location of strong echo was consistent with the location of mesoscale convergence in velocity field; （3） most of the time, the cloud base height of these two processes were 2-3 km, and the cloud top height were around 12 kin; obvious jump of echo top height and vertically integrated liquid （VIL） existed before the generation of storm; the VIL increments of the two processes were 10 kg/m^2 and 20 kg/m^2 and the increments of echo top height were 3 km and 9 kin, respectively; （4） the vertical integrated liquid water contents were relatively stable in the storm development phase, were 40-50 kg/m^2 and 30-40 kg/m^2, respectively; the echo mass center height of the two processes were 4-5 km, and the maximum reflectivity height were 3-6 km at most of the time except June 1, when the sinking movement occurred; （5） downburst probably occurred on June 1 accordine to comprehensive analysis of the information of storm tracking.