2018年8月5日保定一次暴雨过程诊断分析

Analysis of a Rainstorm in Baoding on August 5,2018

利用常规观测资料、雷达产品、NCEP 1°×1°再分析资料、区域加密自动站逐时观测资料,运用天气学原理和天气学诊断方法对2018年8月5日保定的一次区域性暴雨天气过程进行了综合分析。结果表明:本次暴雨过程是由于副高西进北抬和高空西来冷空气相互作用形成的;太行山的迎风坡地形加强上升运动,增大了浅山区降水强度;副高西侧偏南气流配合减弱北上的台风倒槽,在暴雨区上空形成较强水汽辐合,同时涡度、垂直速度等物理量的垂直分布有利于暴雨的产生;华北地区上空具有明显的热力不稳定,暴雨产生于高能舌附近;西部太行山区为低能区控制,有利于暴雨中心出现在浅山区附近;850 hPa暖湿气团带有热带属性。

Based on conventional observation data,radar products,NCEP 1°×1°reanalysis data,and hourly observation data of the regional encryption automatic station,this paper comprehensively analyzed the process of a regional rainstorm in Baoding on August 5,2018 by using the principles of climatology and the diagnostic method of climatology.The results show that the process of the rainstorm is formed by the interaction of the subtropical high into the north and the cold air from the west;The windward slope of Taihang mountain intensifies the upward movement and increases the intensity of precipitation in the shallow mountain area;The southerly airflow on the west side of the subtropical high coordinates with the typhoon trough on the north,forming strong convergence of water vapor over the rainstorm area.Meanwhile,the vertical distribution of physical quantities such as vorticity and vertical velocity is conducive to the occurrence of the rainstorm.;There is obvious thermal instability over north China,and the rainstorm occurs near the high-energy tongue.The taihang mountain area in the west is controlled by low energy area,which is helpful for the rainstorm center to appear near the shallow mountain area.The 850hPa warm wet air mass has tropical properties.