一次低涡切变影响下的舟曲局地短时暴雨天气分析

Analysis of a Local Short-term Rainstorm in Zhouqu Under Influence of a Low Vortex Shear

2016年8月6—7日甘南舟曲局地暴雨天气过程持续时间较久,从6日夜间开始,至7日下午结束,主要降水时段集中,降水强度大,属于局地短时暴雨。形势场500 hPa上西北高、东南低的形势和副热带高压边缘的扰动以及700 hPa上低涡切变对此次降水的形成有重要作用,低层辐合、高层辐散,整层较强的上升运动使暴雨得以发生,垂直速度和散度对暴雨的发生有重要的指示意义。

On August 6-7,2016 in Zhouqu,Gannan,the local rainstorm weather process lasted long,from night of August 6 to the afternoon of August 7,the main precipitation period concentrated,rainfall intensity was strong,belonged to local short-term rainstorm.The situation of high in northwest and low in southeast on 500 hPa,the disturbance of the edge of subtropical high and the shear of the vortex on the 700 hPa played an important role in the formation of the precipitation.The low convergence,high divergence and the strong ascending motion of the whole layer made the rainstorm occur,and the vertical velocity and divergence were important indications for the occurrence of rainstorm.