2009年7月3—4日柳州市大暴雨过程诊断分析

Diagnosis of Heavy Rain in Liuzhou City During 3 to 4 July,2009

对2009年7月3—4日柳州市突发性大暴雨过程利用常规观测资料和卫星资料等再分析资料,进行天气学、动力学诊断和中尺度分析。结果表明:此次柳州大暴雨是由副热带高压、南亚高压、西南涡等系统共同影响产生的;暴雨前对流不稳定能量急剧升高,850h Pa逐渐形成利于水汽辐合的锋面低槽和低空切变线,配合锋区导致不稳定能量的释放;高低空急流给暴雨带来源源不断的水汽输送。

Using the reanalysis data such as conventional observational data and satellite data,the sudden heavy rainfall process of Liuzhou City during 3 to 4 July,2009 was analyzed from meteorology ,dynamic diagnosis and mesoscale.The results showed that the heavy rain in Liuzhou City was generated from the combined effect of these systems, including the subtropical high, south high, southwest vortex;the energy of convective instability rose sharp before the rain;850 hPa frontal trough gradually h^rmed which was favor of moisture convergence and low-level shear line ,which brought about the instability energy releasing with the frontal zone ;jet streams brought a steady stream of water vapor.