一次长三角地区飑线过程的数值预报分析  

Analysis and numerical forecast research on a squall line in the Yangtze River Delta

作　　者：王智[1] 邹兰军[1] WANG Zhi;ZOU Lanjun(Shanghai Central Meteorological Observatory,Shanghai 200030,China)

机构地区：[1]上海中心气象台,上海200030

出　　处：《气象科学》2022年第3期420-426,共7页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(41475040);上海市科委专项(14231202400)。

摘　　要：2019年4月9日,长三角地区发生了一次罕见的长历时强飑线天气过程。在分析其天气形势背景和发展演变基础上,利用新一代华东区域数值模式对此次过程进行了预报分析,初步分析了其演变过程中的中尺度结构特征。结果表明,此次飑线发生在高空槽前、低层强烈辐合抬升天气背景下,强的垂直风切变、冷空气向南侵入与低层暖湿气流叠加建立了强的对流不稳定层结,是飑线发生发展和长时间维持的重要原因。数值模式成功模拟了飑线前部低层暖湿空气上升和后部中层干冷空气下沉这两支入流,以及飑线过境时边界层高度和大气可降水量迅速下降,地面中尺度冷池向东南方向的传播过程,冷池与对流风暴的移动速度基本一致,导致对流前部低层一直有风场的切变辐合抬升,有助于对流维持并发展。An unusually long-lasting severe squall line occurred in the Yangtze River Delta on April 9,2019.Based on weather background and evolution analysis of the squall line,the new generation East China regional numerical model was used to predict and analyze the process,and the mesoscale structure characteristics in the evolution process were preliminarily studied.Results show that the squall line occurred in front of the high trough and under the background of strong convergence and uplift in the lower layer.Strong vertical wind shear,cold air intrusion to the south and warm,humid air flow in the lower layer superimposed to establish a strong convective unstable stratification,which is an important reason for the occurrence,development and long-term maintenance of the squall line.The numerical model successfully simulates the two streams of warm and humid air rising in the lower layer in front of the squall line and dry and cold air sinking in the middle layer in the rear,as well as the rapid decline of boundary layer height and atmospheric precipitable water during the passage of the squall line,and the propagation process of the ground mesoscale cold pool to the southeast.The moving speed of the cold pool is basically the same as that of the convective storm.It leads to the shear convergence and uplift of the wind field in the lower layer in front of the convection,which is helpful to the maintenance and development of the convection.

关 键 词：飑线 华东区域数值模式 中尺度结构特征 冷池 

分 类 号：P435[天文地球—大气科学及气象学]