2020年5月31日佛山超级单体龙卷过程分析
Analysis of Supercell Tornado in Westerly Zone of Foshan on 31 May 2020
中文摘要：
利用常规高空地面观测、广东区域自动站以及广州多普勒雷达等资料对2020年5月31日发生在佛山市高明区的西风带超级单体龙卷天气过程进行分析，结果表明：高层辐散场与中低层弱辐合区叠交，中低层深厚强盛的西南暖湿气流，配合地面辐合线长时间维持，为龙卷超级单体风暴发生发展提供了有利的天气背景；大的CAPE、较强的低层垂直风切变和低的抬升凝结高度为龙卷的发生提供了有利的环境条件；龙卷产生于β中尺度超级单体风暴，雷达探测到较明显的钩状回波、回波悬垂和低层中等强度中气旋，但中气旋尺度较大，龙卷触地前后中气旋直径在6 km以上，龙卷出现在钩状回波顶端和中气旋中心。
中文关键词：
龙卷，西风带系统，环境背景，雷达回波特征，中气旋
KeyWords：
tornado, westly system, weather background, radar echo features, mesocyclone
Abstract：
Based on the data of conventional meteorological observations, Guangdong regional automatic weather stations and Guangzhou Doppler radar, the weather process of westerly supercell tornado occurred in Gaoming District of Foshan City on 31 May 2020 was analyzed. The results show that the high-level divergence field which overlaps with the weak convergence area in the middle and low-level, and the deep and strong southwest warm and humid air flow in the middle and low-level, combined with the long-term maintenance of the surface convergence line, provide favorable weather background for the occurrence and development of supercell storm. Large Cape, strong low-level vertical wind shear and low LCL provide favorable environmental conditions for tornado occurrence. Tornado is produced in meso-β scale supercell storms, and radar detects obvious hook echo, echo suspension and low-level moderate intensity mesocyclone, but the mesocyclone scale is large and the diameter of mesocyclone is more than 6 km before and after the tornado hits the ground, and the tornado appears at the top of hook echo and the center of mesocyclone.