宿迁地区2021年4月30日风雹天气的特征分析

Analysis of the Characteristics of Wind and Hail Weather on April 30th,2021 in Suqian Area

利用MICAPS常规资料、雷达数据以及FNL再分析数据,分析了2021年4月30日宿迁地区一次风雹过程,得出以下3个结论:(1)此次强对流过程的主要环流背景是高层深厚的东北冷涡稳定少动,冷涡底部的前倾槽带来强盛的西北急流,低层西到西南气流输送暖湿空气。地面辐合线是对流过程中重要的触发条件,地面气旋的东移南下在强对流的移动过程中起着重要的作用。(2)此次强对流过程宿迁地区水汽条件差,不稳定层结特征明显,垂直风切变条件好,低层辐合,高层辐散的环境条件以及长时间的强上升运动,使得宿迁地区强对流活动是干对流,出现雷暴、大风和大冰雹。(3)在雷达图上,高耸的强回波、反射率因子和VIL的大值以及中尺度涡旋都是此次冰雹关键的预警特征。

Using MICAPS routine data,radar data and FNL reanalysis data, a hail process in Suqian area on April 30, 2021 is analyzed, and the following conclusions are drawn:(1) the main circulation background of this strong convection process was that the high-level deep northeast cold vortex is stable and less moving, the forward inclined trough at the bottom of the cold vortex brings strong northwest jet, and the low-level West to southwest air carries warm and humid air. The ground convergence line was an important trigger condition in the convection process. The eastward movement and southward movement of the ground cyclone plays an important role in the movement of strong convection.(2)In this strong convection process, the water vapor conditions in Suqian area are poor, the characteristics of unstable stratification are obvious, the vertical wind shear conditions are good, the environmental conditions of lowlevel convergence and high-level divergence and long-term strong upward movement make the strong convection activity in Suqian area dry convection, thunderstorm, gale and hail.(3) On the radar chart, the towering strong echo, the large value of reflectivity factor and VIL and mesoscale vortex are the key early warning features of this hail.