【作者】 赵海军； 刁秀广； 王庆华； 朱义青；

【Author】 Zhao Haijun;Diao Xiuguang;Wang Qinghua;Zhu Yiqing;Linyi Meteorological Bureau;Shandong Meteorological Observatory;

【机构】 山东省临沂市气象局； 山东省气象台；

【摘要】 基于多普勒天气雷达资料,结合中尺度数值模拟结果,对发生在黄淮流域的2次EF2级非超级单体龙卷风暴结构及低层流场结构特征进行了诊断分析。结果表明,2次龙卷过程都发生在副高边缘,低层存在较大的垂直风切变和强烈的水汽辐合;2次龙卷风暴寿命都在2h以上,属于长寿命风暴,而且都有多次及地的共同特征;低层速度产品上有显著的小尺度涡旋特征,涡旋中心相邻距离库之间的速度差>20m?s‐1,对EF2级龙卷预警具有6‐20min的时间提前量;风暴后部中下层相对风暴的速度切变显著加强并迅速下传是诱发20100717龙卷涡旋的主因;风暴顶出现强的辐散,说明风暴内部存在较强的上升气流,风暴底部存在较强的辐合上升运动,从而诱发20120818龙卷涡旋的产生。数值模拟的结果能够较好地再现风暴底部气流结构特征。更多还原

【Abstract】 Based on the Doppler weather radar data,in combination with the mesoscale numerical simulation results, diagnosis analysis are made for two EF2 non supercell tornado in huanghuai watershed. The results show that two non supercell tornado all occurred on the edge of the subtropical high, the lower laminar have larger vertical wind shear and strong water vapor convergence; two EF2 non supercell tornado are long-lived storm,all above 2h and have common feature of many times and to the ground; the lower laminar speed products have significant small-scale vortex features, the speed difference between range bin which are adjacent to the vortex center is more than 20 m·s-1, level of EF2 tornado warning can be advanced for 6-20 min; the main reason that induced the 20100717 tornado vortex is the relative velocity shear which in back of the lower laminar significantly strengthened and rapidly downstream; storm top appears strong divergence can explain that the storm inside have strong updraft, there is strong increased convergence movement at the bottom of the storm, thus induced the20120818 ornado vortex. It can be better reproduced the airflow structure of the bottom of the storm by the numerical simulation results.更多还原