一次西南低涡降水雷达回波结构和演变特征分析

基于新一代天气雷达三维组网等多源气象数据分析了2009年7月30～31日的一次西南低涡触发的强降水天气过程以及主要降水时段雷达回波三维结构及演变特征，研究发现：(1)西南低涡降水与低涡强度发展存在不一致性，强降水出现在低涡强度达到最强之前；(2)中尺度对流系统的发生、发展是此次低涡降水的重要影响因素，西南低涡与中尺度对流系统既相互独立又相互影响，降水是两者共同作用的结果；(3)最强组合反射率因子同样出现在西南低涡发展到最强盛之前，西南低涡能显著影响盆地内降水雷达回波的强度与类型。

Analysis of the Echo Structure and Its Evolution of a Heavy Rain Caused by Southwest Vortex

Based on various multi-source meteorological data including Radar mosaic reflectivity data, the three-dimensional structure and evolution characters of radar echo related to the precipitation process triggered by the southwest vortex occurred during July 30 to 31 in 2009 were analyzed. The main results are as follows, 1.There are inconsistencies between the intensity of the southwest vortex and the precipitation, and the most heavy rain occurred before the southwest vortex is at its strongest. 2.The genesis and development of the mesoscale convection systems are the important factor of the precipitation related to the southwest vortex. The mesoscale convection systems and the southwest vortex are independent but interplay to each other and the precipitation are the result of the interactions. 3. The strongest combined reflectivity factors are occurred before the southwest vortex is at its strongest too. The intensity and the types of the radar echo related to the precipitation in the basin are obviously influenced by the southwest vortex.