一次春季强对流的多普勒雷达产品特征分析

Analysis of Doppler Radar Production Characteristics Through Spring Severe Convection

利用常规高空、地面观测资料及宣城市多普勒雷达资料,对2020年3月21日宣城市的强对流天气过程进行分析,结果显示:高空宽广低槽及中低层西南急流加强是强对流天气发生发展的环流背景。探空图上干下湿的“喇叭口”结构、高低层的冷暖温度平流及中低层的强上升运动,都有利于对流不稳定的维持发展,有利于多单体风暴和超级单体风暴的形成;地面在强对流风暴发展前有中尺度辐合线生成,中低层有钩状回波特征,伴有弱的中气旋,并出现风暴顶辐散,0℃线位于3.5 km左右,-20℃线高于6 km,强对流风暴发展高度偏低,因此并不利于大冰雹产生,但小冰雹发生概率很大。通过研究来提高本地对春季强对流的预报预警水平。

Through using high altitude and ground observational data,and the Doppler radar materials in Xuancheng City,the study analyzes the severe convection weather in Xuancheng City on Mar.21,2020.The results show that the strong convective weather occurred and developed in the background of the circulation of broad trough and southwest jet in the middle and low level.Dry on top and wet on bottom“horn mouth”structure in sounding figure,and temperature changes in high-low layer and strong ascending motion of in middle-low layer are beneficial to sustainable development to cope with unsteady convection,and the formation of multi-cell and supercell storms.Before severe convection storm development,meso-scale convergence line is generated on the ground.In middle-low layer,there are hook-like echo characteristics with weak middle cyclone,and storm top divergence.0℃is located in about 3.5 km,and-20℃in higher than 6 km.The development height of severe convective storm is low.It isn’t conductive to large hail,and the probability of small hail is large.It is suggested to improve the forecast and early warning of local spring severe convection through research.