贵州西南部一次大暴雨环流场风矢量分析

Wind Vector Analysis of a Severe Rainstorm Circulation Field in Southwest Guizhou

利用高空环流背景、中层切边线、地面冷锋、高中低空风量场对发生于2012年5月21日夜间到22日凌晨的贵州西南部大暴雨天气过程进行大尺度环流背景和中尺度对流特征分析,结果表明:此次贵州西南部大暴雨是发生在大尺度环流背景下油地面辐合线逐渐锋生和高低空急流耦与大气层结不稳定形成的,具有典型中尺度强对流特征。各要素场从时间发展与空间演变上与此次大暴雨形成和发展有着密切联系,能较好地反映此次大暴雨降水强度和降水落区变化,要素场时空演变对暴雨发生、发展、衰亡有一定指示意义。

In this paper,the large-scale circulation background and mesoscale convective characteristics of heavy rain in Southwest Guizhou from the night of May 21,2012 to the early morning of May 22,2012 are analyzed by using the high-altitude circulation background,the middle-level tangent line,the surface cold front and the high,middle and low-level air volume field.The results show that the torrential rain in Southwest China occurred in the background of large-scale circulation with the coupling of atmospheric instability and high-low level jet stream,which has typical mesoscale strong convection characteristics.Each factor field is closely related to the formation and development of the rainstorm in terms of time or space evolution,which can better reflect the rainfall intensity and the change of the rainfall falling area of the rainstorm.The temporal and spatial evolution of the factor field has certain indicative meaning for the occurrence,development and decline of the rainstorm.