2023年春季江西南部一次区域性的强对流过程分析

Analysis of A Regional Strong Convective Process inSouthern Jiangxi in Spring 2023

利用常规观测资料和ERA5再分析资料,对江西南部2023年春季一次区域性冰雹、大风等强对流天气的实况和水汽、动力、能量及回波演变特征进行分析讨论。研究结果表明,冷锋和近地面层辐合线是触发2023年3月22日午后大冰雹天气的关键;强垂直风切变、中低层强辐合、高层强辐散和剧烈的上升运动增加大气动力不稳定性;“上干冷,下暖湿”对流不稳定温湿层结及边界层明显θse及能量锋区,为对流的发生和发展提供有利条件;水汽通量辐合大值区与降雹区、强降水区有较好的对应关系;有界弱回波区(BWER)、VIL≥60 kg/m^(2)、高悬的强回波达到-20℃等温线高度以上等特征,对冰雹的发生和落区有较强的指示意义。

Utilizing conventional observation data and ERA5 reanalysis data,the study analyzes and discusses the actual situation of a regional severe convection weather such as hail and strong wind,and the evolution characteristics of water vapor,dynamics,energy and echo in the southern part of Jiangxi province in the spring of 2023.The results show that the convergence line of the cold front and the near-surface layer were key triggers for the large hailstorm on the afternoon of March 22,2023.Strong vertical wind shear,strong convergence in the middle and low layers,strong divergence in the upper layers and violent upward motion increased the atmospheric dynamic instability.The convective unstable temperature-humidity stratification and boundary layer with obviousθse and energy front areas provided favorable conditions for the occurrence and development of convection.There was a good correspondence between the large area of water vapor flux convergence and the hail area and the heavy precipitation area.The bounded weak echo region(BWER),VIL≥60 kg/m^(2),and the high-hanging strong echo reaching above the isotherm height of-20℃have strong indicative significance for the occurrence and fall of hail.