2020年5月17日崇左市极端强降雨过程分析  

Analysis of Extreme Heavy Rainfall Process in Chongzuo on May 17,2020

作　　者：苏彦 唐昌秀 陈少斌 周冬静 SU Yan;TANG Changxiu;CHEN Shaobin;ZHOU Dongjing(Chongzuo Meteorological Bureau,Chongzuo Guangxi 532200)

机构地区：[1]崇左市气象局,广西崇左532200

出　　处：《河南科技》2021年第13期135-138,共4页Henan Science and Technology

摘　　要：运用常规气象观测资料,对2020年崇左“5·17”极端强降雨过程进行成因分析。研究表明:在“5·17”崇左极端强降雨过程中,华北深槽引导冷空气扩散南下,高原不断有短波槽移入广西;低层低涡切变线位于桂中,崇左长时间处于低涡东南侧,西南气流加大,为强降雨输送充沛的水汽和能量;地面场上,强降雨中心与中小尺度辐合中心基本一致。环境条件分析表明,过程中不稳定能量大,抬升凝结高度低,低层有暖平流,暖湿层深厚,对流层中高层有干冷空气侵入,有利于对流的发展和维持。桂西南位于能量舌轴心附近;总温度变温中心对强降雨区有较好的指示作用;中南半岛一带的西南气流是此次强降雨过程的水汽主要来源,桂西南为水汽辐合大值区。卫星云图显示,沿切变有多个中尺度对流云团激发,呈后向传播形势,低层西南气流在强盛暖平流中激发出对流单体;系统移动缓慢,对流云团汇合形成MCC,长时间在崇左上空,造成致灾性强降水。雷达回波特征可见:强降雨云团为回波中心强、回波高度高、VIL值大的深厚对流系统,列车效应使降雨明显增大。Based on the conventional meteorological observation data,the cause of"5·17"Extreme Heavy Rainfall in Chongzuo in 2020 was analyzed.The results show that:during the"5.17"Extreme Heavy Rainfall in Chongzuo,the deep trough in North China led the cold air to diffuse southward,and the short wave trough in the plateau moved into Guangxi continuously.The low-level vortex shear line is located in the middle of Guangxi,Chongzuo is in the south.east of the vortex for a long time,and the southwest airflow increases,which transports abundant water vapor and energy for heavy rainfall.On the ground field,the center of heavy rainfall is basically consistent with the center of small and medium scale convergence.The analysis of environmental conditions shows that the process is characterized by high unstable energy,low rise and condensation height,warm advection in the lower layer,deep warm and wet layer.And invasion of dry and cold air in the middle and upper troposphere,which is conducive to the development and maintenance of convection.Southwest Guangxi is located near the axis of energy tongue;The total temperature variation center is a good indicator of heavy rainfall area;The southwest air flow in Indo China Peninsula is the main source of water vapor in this heavy rainfall process,and Southwest Guangxi is the area with high value of water vapox convergence.The satellite images show that there are several mesoscale convective cloud clusters along the shear,which propagate backward,and the low-level southwest airflow stimulates convective cells in the strong warm advection;The system moved slowly,convective clouds converged to form MCC and stayed over Chongzuo for a long time resulting in disastrous heavy rainfall.The radar echo characteristies show that the heavy rainfall cloud cluster is a deep convective system with strong echo center,high echo height and large VIL value,and the train effect makes the rainfall increase significantly.

关 键 词：极端强降雨 中尺度低涡 西南气流 

分 类 号：P458.121[天文地球—大气科学及气象学]