凉山“6·26”致洪暴雨天气的成因分析  

Analysis of the Cause of the Rainstorm Causing Flood Event Happened on June 26th in Liangshan Prefecture

作　　者：陈文龙 竹利[2] 黄欣 陈朝平[3] CHEN Wenlong;ZHU Li;HUANG Xin;CHEN Chaoping(Meteorological Bureau of Liangshan Prefecture,Xichang 615000,China;Meteorological Bureau of Nanchong City,Nanchong 637000,China;Weather Station of Sichuan Province,Chengdu 610072,China)

机构地区：[1]凉山州气象局,四川西昌615000 [2]南充市气象局,四川南充637000 [3]四川省气象台,四川成都610072

出　　处：《成都信息工程大学学报》2022年第2期202-207,共6页Journal of Chengdu University of Information Technology

基　　金：中国气象局气象预报业务关键技术发展专项资助子项目(YBGJXM(2020)2A-14)。

摘　　要：为提高凉山州致洪暴雨的预报水平,利用地面和高空观测资料、FY-2G卫星的TBB资料、西昌多普勒天气雷达基数据以及NCEP和ECMWF的再分析资料,从天气学角度对2020年6月26日夜间发生在凉山州北部的一次致洪暴雨天气的成因进行诊断分析,结果表明:对流层中层的短波槽和低层具有气旋性曲度的偏南气流为暴雨的产生提供了有利的环流条件;低层偏南风与中尺度低涡后部的东北风形成的中尺度切变线支持了MCC的发展,是强降水发生的主要动力来源;雷达回波表现出显著的逆风区和“列车效应”特征;低层显著的水汽辐合配合深厚的上升运动,以及降水前低层的对流不稳定和斜压不稳定都有利于暴雨的发生。通过对“6·26”暴雨的分析为凉山州致洪暴雨的预报提供了有利的参考依据。In order to improve the forecasting level of flood causing rainstorm in Liangshan Prefecture,based on the surface and high altitude observation data,TBB of Satellite FY-2 G,the base data of the Doppler weather radar of Xichang and the reanalysis data of NCEP and ECMWF,an event of flood causing rainstorm happened,in the northern of Liangshan Prefecture on the night of June 26 th,2020 has been analyzed from the perspective of synoptic viewpoint.The results indicate thatthe short wave trough in the middle level of troposphere and the southerly airflow with cyclonic curvature in the lower level of troposphere provide favorable circulation conditions for the occurrence of rainstorm.The mesoscale shear line formed by the northeasterly wind behind the low-level mesoscale vortex and southerly wind supports the development of MCC,and those are the main power source of rainstorm.The radar echo shows obvious upwind zone and "train effect".The obvious water vapor convergence in the lower layer combined with deeply upward movement,the convective instability and the baroclinic instability in the lower layer before precipitation are the favorable conditions for the occurrence of rainstorm.The analysis of the rainstorm event happened in June 26 th provides a reference for the forecast of rainstorm in Liangshan Prefecture.

关 键 词：中尺度气象学 致洪暴雨 中尺度低涡 辐合 MCC 列车效应 

分 类 号：P458.3[天文地球—大气科学及气象学]