摘要
利用陕西省自动站降水资料和NECP/NCAR再分析资料,对2016年8月24—25日渭河流域暴雨天气进行分析。结果表明:本次暴雨天气是在副高异常强大的情况下发生的,对流层中层冷空气的扩散,低层切变线及地面冷锋是本次暴雨的主要天气系统;流域西部暴雨主要受能量锋及高能区系统影响,以雷电、暴雨为主,中东部受能量锋过境影响,以大风及暴雨天气为主;对流层低层的东北急流为本次暴雨天气提供了水汽主要来源,东北急流与偏南风的交馁造成渭河流域辐合加强,使得短时强降水的产生成为可能;暴雨区散度场从低到高呈现明显的辐合-辐散双重结构,有利于中尺度对流系统的形成和维持;暴雨区垂直速度场出现上升—下沉—上升—下沉分布,当最大值高度值依次降低,有利于对流的发展和维持,最大值高度值呈同一高度分布时对流逐渐减弱。
By using the precipitation data of Shaanxi automatic station and the reanalysis data of NECP/NCAR,the rainstorm weather in Weihe River Basin from August 24 to 25,2016 was analyzed.The results showed that the rainstorm occurred under strong subtropical anticyclone,the cold air diffusion in middle troposphere,the low level shear line and cold front on the ground were the main weather system of the rainstorm;the western area of the river basin was mainly affected by the energy front and high energy region system,with lightning and heavy rain;the middle-east area was mainly affected by energy front transit,with strong winds and heavy rain;the northeast rapids of the lower troposphere provided the main source of water vapor for this storm,the join of northeast rapids and southerly wind caused strengthening convergence,which made the short-time strong rainfall possible;rainstorm divergence from low to high showed a dual structure of obviously convergence-divergence,which was conducive to the formation and maintenance of mesoscale convective system;heavy rain area vertical velocity showed a rise—sink—rise—sink distribution,the decrease of maximum value and altitude value was beneficial to the development and maintenance of convection,and the convection was gradually weakened when the maximum value and altitude value were in the same level distribution.
作者
王英
谢逸雯
高萌
刘帆
胡国玲
Wang Ying;Xie Yiwen;Gao Meng;Liu Fan;Hu Guoling(Xianyang Meteorological Bureau,Xianyang 712000,Shaanxi,China)
出处
《农学学报》
2018年第6期28-32,共5页
Journal of Agriculture
基金
陕西省气象局青年科研基金项目"咸阳强对流天气发生的雷达回波特征参数识别研究"(2016Y-18)
关键词
渭河流域
暴雨
过程分析
Weihe River Basin
Rainstorm
Process Analysis
