贵州一次短历时极端暴雨的形成过程及机理分析  

Formation Process and Mechanism Analysis of a Short-duration Extreme Rainstorm in Guizhou Province

作　　者：吴古会 彭芳 李彦霖 杨帆 陈杨 WU Guhui;PENG Fang;LI Yanlin;YANG Fan;CHEN Yang(Guizhou Provincial Meteorological Observatory,Guiyang 550002,China;Key Laboratory for Mountains Climate and Resources of Guizhou,Guiyang 550002,China;Guizhou Mountainous Meteorological Science Research Institute,Guiyang 550002,China;Qiannan Meteorological Service,Duyun 558000,China)

机构地区：[1]贵州省气象台,贵阳550002 [2]贵州山地气候与资源重点实验室,贵阳550002 [3]贵州省山地气象科学研究所,贵阳550002 [4]贵州省黔南州气象局,都匀558000

出　　处：《高原山地气象研究》2024年第3期38-47,共10页Plateau and Mountain Meteorology Research

基　　金：中国气象局复盘总结专项(FPZJ2023-115);贵州省山地气候与资源重点实验室基金项目(QHLSSLJ[2022]-12);贵州省雨窝创新团队项目(黔气科合TD[2024]01)。

摘　　要：利用地面常规观测及加密自动站观测资料、FY-4A卫星云图、多普勒天气雷达和风廓线雷达产品、ERA5再分析资料,对2022年5月29日贵州中南部的一次打破历史记录的短历时极端暴雨过程,从其形成过程和形成机理等方面进行了分析。结果表明:(1)此次短历时极端暴雨是在典型的低槽冷锋形势下,由中-β尺度低涡和地形的共同作用造成;对流发生前,异常高的整层可降水量、低层强烈的水汽辐合、显著的水汽垂直递减率为短历时强降水提供了有利的水汽条件。(2)最强降水发生在MCC的形成和维持阶段,TBB的强度变化与降水强度变化一致,TBB最低值和10 min最强降水在同一时段发生;暴雨中心区受“人”字形回波和多个低质心的强回波单体重复影响,形成短历时极端强降水。(3)对流单体沿锋面及锋生区生成发展,锋前静力不稳定层结、低层辐合、高层辐散的有利配置使得对流移经时得到维持和增强,中-β尺度低涡、冷池和地形的共同影响也提供了维持条件,而对低涡、冷池和地形作用的把握不足是造成预报偏差的主要原因。Based on ground conventional observation data and intensive automatic station observation data,cloud image of FY-4A satellite,Doppler radar data,wind profile radar data and ERA5 reanalysis data,a short-duration extreme rainstorm which broke the historical record in southern Guizhou on 29 May 2022 were analyzed from formation process and mechanism.Results are as follows:(1)The short-duration extreme rainstorm was caused by the combination of medium-βscale vortex and topography under a typical low-trough cold front type.Before the convection,the abnormally high precipitable water of the whole layer,the strong water vapor convergence in the lower layer and the significant vertical water vapor lapse rate provided favorable water vapor conditions for the short-duration heavy precipitation.(2)The strongest precipitation occurred in the formation and maintenance stage of MCC,and the change of TBB intensity was consistent with the change of precipitation intensity,the lowest value of TBB and the strongest precipitation in 10 min occurred at the same time.The rainstorm center area was affected by the herringbone shape echo and several strong echo units with low quality cores repeatedly,resulting in short-duration extreme heavy rainfall.(3)Convective cells developed along the front and frontogenetic regions,the prefrontal statically unstable stratification,convergence at low level and divergence at high level made the convection maintenance and enhancement.The combined influence of medium-βscale low vortex,cold pool and topography also provided the maintenance conditions,the main reason for forecast bias was insufficient consideration of the effects of medium-βscale low vortex,cold pools and terrain.

关 键 词：短历时极端暴雨 MCC 中-β低涡 冷池 地形作用 

分 类 号：P458.121.1[天文地球—大气科学及气象学]