两次龙舟水降水过程中不同类型的天气雷达特征分析

对2013年5月20日和5月22日由南海季风造成的两次龙舟水过程进行了多普勒雷达资料分析,结果表明:造成雷雨大风的飑线过程具有人字形特征,之后分裂为两条弓形回波,此飑线具有前倾结构、高质心高度、高VIL、共存多个中气旋、中层径向辐合、速度模糊等特点,雷雨大风是由飑线前后两侧的下击暴流造成的;形成列车效应的带状回波具有低回波顶高、低质心高度、中气旋、急流核高度低等特点,短时强降水中局部地区的大风是由环境风造成。

Analysis of the Characteristics of Weather Radars of Different Type During Two Processes of Rain Around Traditional Dragon-Boat Racing Festival

Two processes of rain on May 20 and 22, 2013 （during the annual traditional festival of dragonboat racing） are analyzed using Doppler data. The result is as follows. A squall line that caused thunderstorm and gale was split into two branches but with one end connected to each other initially and then separated from each other completely afterwards. The squall is characteristic of a front-leaning structure, a center of mass at high levels, high VIL, coexistent multiple mesocyclones, mid-level radial convergence and veloci- ty ambiguity. The thunderstorm and gale were caused by downbursts at the front and rear of the squall. Having the so-called train effect, echoes were stripe-shaped, featuring low echo top, low center of mass, meso- cyclone and low jet-stream core. The gale in some part of the short-range intense rain resulted from the ambient wind.