一次伴随冰雹的超级单体风暴特征

Characteristics of a Super-Cell Storm with Hail

利用中国气象监测网实测资料、重庆西部多普勒天气雷达资料及NCEP/NCAR 6 h间隔1°×1°再分析资料,对2008年6月5日发生在重庆市中部的大风冰雹天气过程进行了天气背景、物理量、雷达回波和云图特征分析。研究表明:大气中显著的水平风切变和垂直风切变及晴空太阳辐射对地面的不均匀加热都有利于诱生涡度;从北部高层向南侵入对流层低层的干冷空气有利于大气对流不稳定结构的维持,对流层低层比湿加大,对流有效位能(CAPE)增加,是对流风暴发展的重要条件;从高纬度沿等熵面下滑的高位涡(大于1 PVU)有利于中纬度超级单体(中气旋)风暴的发生和发展。在雷达回波结构上有中气旋、高悬强回波核、弱回波区、回波墙、虚假回波、回波强度梯度大等超级单体风暴特征;在可见光卫星云图上有上冲云顶和积雨云羽特征。最后讨论了超级单体风暴的预报要点。

A hail event with a gale occurred on 5 June 2008 is analyzed from the aspects of the synoptic circulation background,physical quantities,and the characteristics of radar echoes and cloud pictures by means of observational data from the Meteorological Observation Network of China,Doppler weather radar data from the western Chongqing,and NCEP/NCAR 1°×1° reanalysis data.It is demonstrated that the vertical and horizontal wind shear and the clear sky solar radiation,which resulted in uneven surface heating,were apt to the vorticity genesis.The dry-cold air in the upper troposphere intruded into the lower layer favored the maintenance of convective instability,and the increasing of specific humidity and CAPE in the lower troposphere was essential to the development of the convective storm.The high potential vorticity（greater than 1 PVU） contributed to the genesis and development of the super-cell storm（meso-cyclone）.The features of a super-cell storm can be found,such as the strong overhanging echo core,false echo,meso-cyclone,weak echo and echo wall,large echo intensity gradient,etc.,and there existed the cumulonimbus plume and up-rushing cloud top in the visible satellite imagery（VIS）.Some forecast clues are concluded for super-cell storms.