摘要
利用常规气象资料及多普勒天气雷达、卫星、中尺度自动气象站等资料,采用天气学诊断分析方法,对2019年5月27日广西靖西市极端暴雨成因及可预报性进行分析。结果表明,(1)极端暴雨是在有利的大气环流形势下,高空槽与地面冷空气共同作用下产生,极端暴雨出现在850hPa切变线南侧低层西南急流与东南风辐合区中;(2)对流主要在850hPa切变线、地面辐合线及迎风坡与偏南风的辐合上升区中触发,冷池出流与山前爬升的偏南暖湿气流产生的剧烈上升运动有利于中尺度对流系统发展维持,低质心暖云降水回波形成的列车效应是极端强降水产生的直接原因;(3)EC-HR模式与SHANGHAI_HR区域模式均没有预报出低层东南风影响,可能是模式雨量预报偏弱的主要原因。
Based on conventional meteorological data,and data of Doppler weather radar,satellite,and mesoscale automatic weather station,the causes and predictability of extreme rainstorm in Jingxi City,Guangxi Zhuang Autonomous Region on May 27,2019 were analyzed by using synoptic diagnostic analysis method.Under beneficial atmospheric circulation situation,the extreme rainstorm was produced under the joint action of the high trough and the cold air on the ground.The extreme rainstorm occurred in the convergence area of southwest jet and southeast wind in the lower layer of the south side of 850 hPa shear line.Convection was mainly triggered in the 850hPa shear line,the surface convergence line,and the convergence ascending region of the windward slope and southerly wind.The upwelling of cold pool outflow and south warm moisture flow climbing in front of the mountain was beneficial to the development and maintenance of mesoscale convective system.The"train effect"formed by the precipitation echo of low centroid warm cloud was the direct cause of extreme heavy precipitation.Neither the EC-HR model nor the SHANGHAI_HR regional model predicted the effect of low-level southeast winds,which may be the main reason for the weak rainfall forecast result of the model.
作者
周云霞
翟丽萍
何珊珊
Zhou Yunxia;Zhai Liping;He Shanshan(Guangxi Meteorological Observatory,Nanning 530022)
出处
《气象研究与应用》
2020年第2期68-74,共7页
Journal of Meteorological Research and Application
基金
广西气象科研计划重点项目(桂气科2017Z02)
广西自然科学基金项目(2018GXNSFBA281178)。
关键词
极端暴雨
中尺度对流系统
列车效应
可预报性
extreme rainstorm
mesoscale convective system
train effect
predictability
