摘要
利用常规观测资料和自动站、加密雨量站、多普勒雷达等资料,对2007年8月9日凌晨鄂西北郧西县马安乡一次局地大暴雨天气进行了分析,重点分析了此次过程的多普勒天气雷达观测资料。结果表明:降水回波由非强风暴对流单体向强风暴对流单体演变造成马安大暴雨;地形作用、回波合并效应使对流发生发展,回波少动使降水维持;中小尺度系统活动频繁,使对流加强,降水持续、升级;主要降水由一强风暴对流单体造成,并有中气旋出现,中气旋直接引发强暴雨;垂直积分液态水含量变化可为判断风暴发展和风暴降水提供有效信息;中气旋、逆风区等中小尺度结构特征对强风暴及暴雨预报有很好的指示作用;反射率因子、平均径向速度、综合切变等产品对强天气现象的识别以及在暴雨分析预报中具有实用意义。
An analysis for the local rainstorm which occurred at the Ma＇an township of Yunxi county on 9 August 2007 is performed with the conventional observation data,the rainfall data of automatic precipitation stations,the intensive observations,the Doppler-Radar data and etc.The results indicate that the development of precipitation echo from the general convective cell to severe convective cell results in the rainstorm in Ma＇an.Topographic effects and cell combination triggers make the convection occurred and developed,nevertheless cell seldom moving makes the rainfall continuous.The frequent movements of the meso-and micro-scale system makes the convection reinforced and the rainfall continued and even upgraded.The main rainfall is caused by a severe convective cell with an occurrence of mid-cyclone,and the mid-cyclone results directly in the severe rainstorm.The variations of vertically integrated liquid can be taken as an effective criterion of the development and precipitation of rainstorm.Meso-and micro-scale structural features of mid-cyclone and weak echo area have significant indications for the severe storm and rainstorm forecast.The products such as radar reflectivity factors,mean radial velocity,integrated shear and so on have a practical significance in the severe weather identifying and the rainstorm forecast.
出处
《暴雨灾害》
2009年第3期246-250,共5页
Torrential Rain and Disasters
关键词
大暴雨
雷达资料
强风暴
中小尺度系统
中气旋
Rainstorm
Radar data
Severe storm
Meso-and micro-scale system
Mid-cyclone
