2017年7月广西柳州一次特大暴雨过程成因分析  

The Cause Analysis of an Extremely Heavy Rainstorm in Liuzhou,Guan-gxi Zhuang Autonomous Region in July 2017

作　　者：蓝柳茹 刘蕾 李亚琴 苏小玲 LAN Liu-ru(Liuzhou Meteorological Bureau, Liuzhou, Guangxi 545001)

机构地区：[1]广西壮族自治区柳州市气象局,广西柳州545001

出　　处：《农业灾害研究》2019年第1期45-49,68,共6页Journal of Agricultural Catastrophology

摘　　要：利用常规观测资料、区域自动站资料、NCEP/NCAR FNL 1°×1°再分析资料和雷达资料,对柳州2017年7月1—2日的特大暴雨过程进行诊断分析。结果表明,此次强降雨发生在西太平洋副热带高压和南亚高压稳定维持的环流背景下,由高空槽、低涡切变、中低空急流和地面冷空气共同影响产生。前期降水主要在柳州北部,为暖区暴雨,降水"列车"效应和地形抬升作用显著;后期降水强度更强,主要在柳州南部,为锋面降水,对流性降水明显。低空急流尤其是超低空急流为暴雨提供了充足的水汽。在南压高压东侧的强烈"抽吸"作用下水汽上升运动强烈发展,为暴雨提供了有利的动力条件。暴雨发生前不稳定能量累积和中层干冷空气侵入造成的深厚不稳定层结触发了明显的短时强降水。Based on conventional meteorological data, regional automatic station data, NCEP/NCAR FNL 1°×1° reanalysis data and Doppler radar data, diagnostic analysis of the server heavy rainfall occurred in Liuzhou during 1-2 July 2017 was discussed. The results showed that the heavy rainfall occurred under the circulation background that Western Pacific Subtropical high and South Asia high remained stable. The upper trough, vortex shear line, the jet at the middle-lower level and surface cold air gave rise to the excessive rainfall. The prior period rain was warm-sector rainfall, locating primarily in the north of Liuzhou, the remarkable rain “train” effect and topographic lifting played an important part in it. The later period rainfall was frontal precipitation, mainly situating in the south of Liuzhou, which was more fierce than the former. Convective precipitation was evident in later period. The low-level jet produced plentiful vapor for the formation and continuation of rain gush, especially the supply of the ultra-low-level jet. Severe ascending air developed strongly under the influence of the “pumping” action in the east of South Asia high, which offered favorable dynamic conditions for the heavy rainfall.

关 键 词：高空槽 低涡切变 超低空急流 干冷空气 深厚的不稳定层结 

分 类 号：P458.121.1[天文地球—大气科学及气象学]