黔东南山区2次大暴雨过程对比分析

Comparative Analysis of Two Times Heavy Rain Process in Qiandongnan Mountain Area

利用常规观测资料、物理量场、16个县市地面自动站及区域站观测资料等,对比分析了2014年7月3日夜间~4日白天与2015年6月17日夜间~18日白天黔东南州的2次大暴雨天气过程。结果表明,2次暴雨天气过程的主要影响系统是由于西太平洋高压稳定少动,对高空槽、中低层江淮低涡切变、梅雨锋西段的移动造成阻挡,致使切变系统在贵州长时间停滞而出现暴雨、大暴雨天气过程;2次过程黔东南均受副热带高压外围偏西南气流影响,700~850 h Pa的切变线几乎重合,中高纬度均有冷平流和高空槽的共同影响;水汽、能量、动力等方面均具备降大暴雨条件,暴雨中心均出现在黔东南的西部地区,暴雨集中时段均出现在夜间。第2次过程的直接经济损失没有第1次过程大,但2015年因滑坡泥石流掩埋死亡2人事故;第2次过程暴雨的量级比第1次过程的范围更大、强度更强。

Using conventional observation data,physical quantity,data of automatic station and regional station in 16 counties and cities,two times heavy rain process in Qiandongnan Prefecture during Jul.3 night-Jul.4 daytime in 2014,Jun.17 night-Jul.18 daytime in 2015 were compared and analyzed.The results showed that due to stability of Western Pacific high pressure,upper trough,Jianghuai vortex shear,movement of western part of Meiyu front was blocked,resulting in a long time stagnation of shear system in Guizhou;two times heany rain process in Qiandongnan Prefecture were affected by the subtropical high pressure periphery southwest airstream,700 to 850 h Pa shear line were almost coincided;the heaby storm center all appeared in the western region of Qiandongnan and cencentrated at night.The economc loss of the second process was less than that in the first heavy rain process.The magnitude of the second process was greater than that of the first process,and the range was larger,the intensity was stronger.