广西临桂极端大风天气过程的中尺度特征分析

Mesoscale characteristic analysis of extreme gale weather in Lingui,Guangxi

利用常规观测资料、桂林多普勒天气雷达资料,对2019年3月21日夜间广西桂林市临桂区极端大风天气过程的气象要素变化特征、对流潜势和对流风暴的中尺度特征进行分析。结果表明,这是一次由超级单体造成的下击暴流过程,极端大风出现在最强分钟降水之前,气压在极端大风出现前后变化剧烈;过程发生在冷锋前低空急流前端的不稳定层结下,地面中尺度辐合中心触发对流,在强的风切变环境下迅速发展成超级单体风暴;雷达图上具有前侧入流缺口、后侧弱回波通道、回波悬垂、强中气旋、地面强辐散等特征;雷达提前一小时识别出TVS,在今后的临近预警中值得高度重视。

Using conventional observation data and Guilin Doppler weather radar data,the meteorological elements characteristics,convective potential and mesoscale characteristics of convective storms in the extreme gale weather process in Lingui District,Guilin,Guangxi at night on March 21,2019 were analyzed.The results showed that this was a downburst process caused by supercells.The extreme gale appeared before the max minute precipitation,and the pressure changed drastically before and after the extreme gale.The process took place under the unstable stratification at the front of the low-level jet in front of the cold front,and the surface mesoscale convergence center triggered convection,which rapidly developed into a supercell storm in the strong wind shear environment.The radar chart had the characteristics of an inflow gap on the front side,a weak echo channel on the rear side,an echo overhang,a strong medium cyclone,and strong ground divergence.The radar recognized the TVS one hour in advance,which deserved high attention in the near-warning in the future.