2022年3月荆门春季首场暴雨形成机制分析

Analysis on the Formation Mechanism of the First Spring Rainstorm in Jingmen in March 2022

利用常规气象资料、风云卫星云图、雷达及地面观测资料对荆门2022年3月16日首场春季暴雨的形成机制进行诊断分析,结果表明:(1)高空强辐散、500 hPa高空槽东移、中低层低涡切变线、低空急流加强东移北抬、地面冷空气入侵暖低压倒槽等天气系统配置,是这次春季暴雨发生的有利天气背景。(2)这次暴雨发生前的环境场特点为适中的对流有效位能,较大水汽含量及上干冷、下暖湿极,说明强对流天气为短时强降水及雷暴大风。(3)华北冷空气沿地面倒槽后部侵入,沙洋西部的西北风与东部的偏东风形成地面辐合线,触发对流天气,造成沙洋的短时强降水。(4)与中尺度对流云团移动相对应,宜昌地区有中尺度对流单体生成,其东移中加强并在荆门南部形成弓形回波,雷达回波图上强的反射率回波对应卫星云图上有TBB低值区,说明对流云发展高度高,垂直运动剧烈,造成荆门南部短时强降水和雷暴大风。

The formation mechanism of the first Spring Rainstorm in Jingmen on March 16, 2022 was diagnosed and analyzed by using conventional meteorological data, Fengyun satellite cloud images, radar and ground observation data. The results show that:(1)the weather system configurations such as high-altitude strong divergence, 500 hPa high trough moving eastward, low-level vortex shear line, trough were the favorable weather background for the spring rainstorm.(2) The environmental field before the rainstorm was characterized by moderate convective effective potential energy, large water vapor content and upper dry and cold, lower warm and wet poles, indicating that the severe convective weather was short-term heavy precipitation and thunderstorm gale.(3) The cold air in North China intruded along the back of the surface inverted trough. The northwest wind in the west of the Shayang and the easterly wind in the East formed a ground convergence line, triggering convective weather and causing short-term heavy precipitation in the Sha Yang.(4) Corresponding to the movement of mesoscale convective cloud clusters,mesoscale convective cells are formed in Yichang area, which are strengthened in the eastward movement and form bow echo in the south of Jingmen. The strong reflectivity echo on the radar echo map corresponds to the low TBB value area on the satellite cloud map,indicating that the convective cloud has a high development height and intense vertical movement, resulting in short-term heavy precipitation and thunderstorm gale in the south of Jingmen.