长治市一次暴雨天气过程的雷达回波分析

Radar Echo Analysis of the Rainstorm in Changzhi City

利用常规气象观测资料、自动站及区域加密资料,对2017年7月26日—29日出现在长治市的暴雨天气进行大尺度环流背景、中低层影响系统、雷达产品的综合分析。结果表明:本次暴雨天气过程主要受低压槽、副热带高压、700 hpa和850 hpa切变线等系统的影响。副热带高压外围为此次强降水带来持续不断的水汽供应;暖湿空气与低压槽后分裂南下的干冷空气在市上空汇合以及低层切变线的稳定维持,增强了大气层结不稳定度。不稳定大气层结在冷空气的触发下以及系统的稳定维持,致使长治市市出现强降水天气过程,雨量最大达185.9 mm。

Using conventional meteorological observation data,automatic stations and regional encrypted data,a comprehensive analysis of the large-scale circulation background,low-and middle-level impact systems,and radar products was carried out on the rainstorm weather process that occurred on July 26 to July 29,2017 in Changzhi City.The results show:The main impact system of this rainstorm weather process is low pressure trough,subtropical high pressure,700hpa and 850hpa shear lines.The outer periphery of the subtropical high pressure brought continuous water vapor supply to the heavy precipitation;the confluence of warm and humid air and the cold cold air splitting south after the low-pressure trough split over the city and the stable maintenance of the low-level shear line enhanced the instability of the atmospheric junction.The unstable atmospheric structure is triggered by cold air and the system is maintained steadily,resulting in a severe precipitation weather process in our city,with a maximum rainfall of 185.9 mm.