2018年5月16日宿迁市一次雷暴大风天气过程分析

Analysis of a Thunderstorm and Strong Wind Weather Process on May 16,2018 in Suqian City

利用MICAPS常规资料、地面加密观测资料和FNL 0.25°×0.25°再分析资料,分析2018年5月16日发生在宿迁地区雷暴大风天气过程的天气形势、环境条件和多普勒雷达回波特征,结果表明:(1)此次雷暴大风过程的影响系统是低涡切变线和西南风急流,地面辐合线是此次强对流过程的触发机制;探空曲线呈上干下湿的“喇叭口”结构,层结不稳定;较强的垂直风切变和整层上升运动使对流得以发展和维持。(2)反射率因子图上呈现出明显的弓形回波和阵风锋特征,低仰角径向速度图上有大风速中心,出现速度模糊,并探测到中气旋,VIL值有明显的跃增后快速减小,表明强的下沉气流快速下冲,导致雷暴大风的发生。

Using MICAPS conventional data,ground-intensified observation data and FNL 0.25°×0.25°reanalysis data,the weather situation,environmental conditions and Doppler radar returns of the thunderstorm and gale process that occurred in Suqian on May 16,2018 were analyzed.According to the wave characteristics,it was found that:(1)The influence system of this thunderstorm and strong wind process was the low vortex shear line and the southwest wind jet,and the ground convergence line was the trigger mechanism of this strong convective process;the sounding curve was dry at the top and wet at the bottom The bell mouth structure,the stratification was unstable;the strong vertical wind shear and the upward movement of the whole layer enable the development and maintenance of convection.(2)The reflectivity factor map presents obvious bow echo and gust front characteristics,and the low-elevation radial velocity map has a large wind speed center,and the speed was blurred,and a mesocyclone was detected,and the VIL has an obvious jump and then rapidly Decrease,indicating that the strong downdraft rapidly descends,leading to the occurrence of thunderstorms and high winds.