【摘要】 利用现场灾调资料、Micaps资料、地面加密自动站和广州SA雷达资料等，对2018年8月31日广州番禺龙卷天气过程进行分析。结果表明：该次龙卷发生在14:25前后，路径长度约80 m,最大破坏宽度约52 m,破坏等级为EF1级。龙卷发生在季风低压活动天气背景下，中低空西南急流的叠加交汇及低层辐合、高层辐散的配置为龙卷的发生提供了有利的天气尺度条件；较大的对流有效位能、深厚的湿层和极低的抬升凝结高度为龙卷的发生提供了充足的对流不稳定能量和水汽条件；较大的低空垂直风切变、较大的风暴相对螺旋度和较大的能量螺旋度，为超级单体风暴的发生提供了有利的动力条件，地面中尺度辐合线和小尺度涡旋是对流风暴触发的有利中小尺度系统；龙卷产生在微型超级单体风暴中，伴有弱中气旋，龙卷触地前后伴有风暴质心明显下降、中气旋强度增强和直径尺寸明显缩小等特征。更多还原

【Abstract】 Using on-the-spot disaster investigations, Micaps data, intensive surface automatic weather stations data and data from a synthetic aperture radar in Guangzhou, this work analyzes the weather process of a tornado in Panyu, Guangzhou on August 31, 2018. The results are shown as follows. The tornado happened around 14:25 on a path that was about 80 m in length and 52 m in the swath of most destructive power, recorded at the destruction grade of EF1. Against the weather background of a monsoonal low pressure, the tornado was generated under favorable synoptic conditions as a mid-level southwesterly jet stream met and superimposed with a low-level one, with low-level convergence allocated with upper-level divergence. The genesis of the tornado was supplied with sufficient amount of convectively unstable energy and water vapor as there was large convective available potential energy, a deep moist layer and a very low lifting and condensation height. The genesis of a supercell storm was made dynamically possible as it was supplied with large low-level vertical wind shear, large relative storm helicity and energy helicity. A surface mesoscale convergence line and a fine-scale vortex were the right meso-and fine-scale systems for the triggering of the convective storm. Generated in a micro-scale supercell storm, the tornado was accompanied with a weak mid-cyclone, and the storm mass core dropped significantly in height, the mid-cyclone much intensified and its diameter much shrank around the touch-down of the tornado.更多还原