2010年7月海河流域一次暴雨过程成因分析

Cause Analysis of Heavy Rainfall Process in Haihe River Valley in July 2010

利用常规气象观测资料及NCEP再分析资料,对2010年7月18—20日海河流域暴雨过程进行了天气学诊断分析。分析结果表明:本次暴雨过程的主要影响系统是高空低涡及低空暖切变,暴雨是产生在前期大气对流不稳定区域里,暴雨期间对流层中低层的辐合及上升运动为暴雨的产生提供了动力条件,亦是本次暴雨动力场结构的主要特征,而西南暖湿气流的不断加强促使水汽在暴雨区上空汇合,源源不断的水汽输送和强烈的水汽辐合,为暴雨的形成和持续提供了充足的水汽条件。

By using of the routine observation data and NCEP reanalysis data,the synoptic diagnostic analysis for heavy rainfall process on July 18—20,2010 in the Haihe river valley is performed.The results show that the main influencing systems include the southwest vortex and the lower level warm shear line.The heavy rain originated in the preliminary instable atmospheric convection region,convergence and ascending movement in the low and medium layer provided favorable dynamic condition for the formation of heavy rain,which is the main feature of the heavy rainfall dynamic field structure.The intensification of the southwest stream made the water vapor flow to the heavy rain region,and the water vapor transmission and convergence provided sufficient moisture for the formation of heavy rain.