浙中金华地区“2013.3.20”春季雷暴天气过程研究分析

为了探索春季强对流发生发展的机制,利用常规观测资料、MICAPS资料以及新一代多普勒天气雷达资料,采用天气学诊断方法,对2013年3月20日凌晨发生在浙中金华地区的一次大范围的强雷暴天气过程进行分析。结果表明:(1)高空槽和地面倒槽是此次强对流天气过程的主要影响系统;(2)高空三层为一致的西南急流,水汽输送强;(3)中低层急流附近存在强的垂直上升运动中心且几乎重合,500hPa到地面存在强的垂直风切变,动力条件好;(4)中低层深厚的暖平流与高层弱冷平流相互作用形成了上干冷、下暖湿的不稳定层结;(5)中层冷空气渗透,促使强对流进一步发展,风暴发展为中-β尺度飑线系统,但前沿无阵风锋产生;(6)飑线南段的超级单体风暴发展为非超级单体强风暴,在雷达图上表现为"弓形"回波,其顶点经过武义站时造成27.4m/s(10级)的瞬时大风;(7)VIL高值维持时间较短,不利于冰雹出现。

The Analyses of a Spring Thunderstorm Weather Process in the Region of Zhejiang central of JinHua on the Mar 20th in 2013

In order to find out the development mechanism of severe convection in spring,with conventional observation data,MICAPS data,and a new generation doppler weather radar data,a wide range of severe convection weather,happened in the morning on March 20,2013 in Jinhua,was analyzed by synoptic and dynarnieal methods which.The results show that：（1） The main influencing system is upper trough and ground inverted trough; （2） The water vapor transport is strong in the process,because three high-layers are all controlled by southwest jet; （3） The dynamic condition is ideal,for there are severe vertical ascending motion centers almost overlapping near the jet and the vertical wind shear is strong from 500hPa to the ground; （4） The interaction between strong warm advection in lowlevels and weak cold advection in high-level leads to the unstable stratification with warm-wet air under dry-cold air;（5） Cold air infiltering from middle-level prompts the further development of strong convection,the storm develops into a meso-seale squall line without any gust front; （6） The supercell storm in the south of squall line develops into a non-supercell storm with the feature as ＂bow＂ echo in radar product,and the top of the echo brings instantaneous wind of 27.4 m/s when it passes Wuyi; （7） VIL high value maintains in shot time that hail can hardly occur.