2014年初夏喀什地区一次罕见的暴雨到大暴雨过程的综合分析

Analysis of a Rare Rainstorm Process in the Early Summer of 2014 in Kashgar Region

摘要: 应用常规气象观测资料、区域自动逐渐时观测资料、NCEP 1˚ × 1˚再分析场资料、FY-2号气象卫星资料及新一代天气雷达资料，对2014年6月18~23日喀什地区罕见连续性暴雨天气过程环流背景、高低空风场、物理量场及卫星雷达资料进行天气学诊断分析。结果表明：此次暴雨过程分为两个时段，两个时段暴雨影响系统不同，第一时段为典型“东西夹攻”造成的复合型降水，第二时段为巴湖低涡引导冷空气南下与东移北收的中亚低槽合并造成对流性降水。中亚低涡、巴湖低涡和中低层切变是这次暴雨天气过程主要影响系统；中层西南气流、低层东风气流为暴雨产生提供充沛水汽；低层辐合、高层辐散配置，使垂直上升运动得到发展和加强，低层水汽迅速向上输送，同时引起热量、动量垂直输送，为暴雨形成提供有利动力和热力条件。地形在本次强降水过程中有重要作用，地形抬升和收缩作用使得辐合上升运动加强。

Abstract: By using conventional meteorological observation data, hourly precipitation data by regional automatic stations in Kashgar, 1˚ × 1˚ reanalysis data of NCEP, FY-2 satellite data and radar data, the circulation background, physical quantity, upper and low altitude wind field of a rare rainstorm in Kashgar on June 18-23 of 2014 were analyzed. The results show that the rainstorm process was mainly divided into two periods, for the first time was a typical complex precipitation, for the second time was the convectional precipitation caused by the Balkhash lake low vortex and central Asia trough mergers. The central Asia low vortex, the Balkhash lake low vortex and low-level shear were the major influence systems of this heavy rainfall, the southwest middle level jet and the lower east wind provided plenty of moisture condition for this weather process. Low-level convergence and upper level divergence configuration made vertical upward movement developed and strengthened and water vapor at low level was transported upward rapidly, at the same time, the vertical transportation of heat and momentum occurred, these all provided a favorable dynamic and thermodynamic condition for the heavy rain formation.