连续两次冰雹天气过程的多源资料分析

Analysis of two successive severe hailstorm event based on multi-source date

运用多源探测设备资料,对2018年3月12—13日发生在贵州省中西部地区的连续两次冰雹天气过程的大气环流场、环境物理量和对流单体结构特征做了综合分析,得到以下结论:全省受南支槽前西南气流影响,地面辐合线和低层暖平流为省西部边缘低涡的发展和维持提供动力条件,贵阳微波辐射计观测到的水汽参量在强对流过程到达前均有波动增长,在对流系统过境期间达到峰值,层结稳定度参数也反映出同样的特征,系统过境期间层结不稳定增大。冰雹前期中高空层的“干侵入”结构增强了环境位势不稳定度,过程期间低层风场具有较强的辐合运动,多个对流单体在移动过程中合并成为一个有组织的对流系统,并得到第二次发展,雷达回波强度达到60 dBz以上,回波顶高达到11 km以上,强度≥45 dBz回波延伸至-20℃温度层高度以上,从而造成贵州中西部连续两次冰雹灾害天气。

The multi-source date were used to investigate the atmospheric circulation,environmental physical field values,structures and formation mechanism of severe convective systems on 12-13 May 2018 in west and center of Guizhou Province.The results indicate that:Controlled by warm wet flow coming from southwest,the convective cell generate and enhance continually in the south of Guizhou Province.The surface convergence line and warm advection in low level.Based on the data obtained with a ground based microwave radiometer in Guiyang,the parameters of vapor show fluctuation before the severe convective system appears and reach peak value in transit,the parameters of stratification stability show the same characteristics.The dry intrusion in the middle and top of troposphere may be conducive to the enhancement of potential instability,the air convergence area in the vertical direction keeping steadily,multiple convective cells merged into organized convection system and enhanced again,the radar echo intensity≥60 dBz,echo top hight≥11 km,the strong echo(≥45 dBz)develop upward the-20℃level height.All of that is the reason of the severe hailstorm event in center and west of Guizhou province.