江西北部2次大暴雨过程对比分析

Comparative Analysis of Two Rainstorm Processes in the North of Jiangxi

利用Micaps常规资料和fnl资料,对2013年5月江西北部2次大暴雨天气过程("5.07"和"5.14")的大尺度环流形势、低空急流、水汽输送、垂直运动和中尺度系统,以及多普勒天气雷达拼图回波特征等要素,采用对比方法进行分析,结果表明:1)2次大暴雨过程欧亚中高纬环流形势均为两脊一槽型,但降水性质、环境条件和中尺度特征有所差异;2)"5.07"大暴雨低空急流具有脉动性,而"5.14"大暴雨中低空急流一直维持;3)"5.14"大暴雨过程的水汽和动力条件都比"5.07"大暴雨过程强;4)"5.07"大暴雨过程以带状回波为主,范围狭长局地性较强;"5.14"大暴雨过程以絮状回波为主,范围宽广持续时间长较为均匀。

Based on the routine observational data of Micaps and NECP reanalysis data,a comparative analysis on large-scale circulation,low-level jet （ LLJ）, transportation of water vapor, vertical motion, mesoscale systems and radar echoes of two torrential rain processes in north of Jiangxi province in May 2013 （＂5.07＂and＂5.14＂） was analyzed. The results showed that.1 ）The two processes both belong to the type of ＂two ridges and one trough ＂ of the circulation in Eurasian high latitudes,but their precipi- tation nature ,environmental conditions and mesoscale characteristics are different. 2）The LLJ in the ＂5.07＂ heavy rain process experienced a process of strengthening,weakening with moving eastward, reinforcing again and then weakening with moving eastward a second time ,but the LLJ in the ＂5.14＂ heavy rain process has been maintained strongly. 3）The ＂5.14＂ heavy rain process was stronger than the ＂5.07 ＂heavy rain process whether in water vapor or dynamic conditions. 4）The radar echoes in the ＂5.07＂ heavy rain process were convective precipitation echoes with narrow range and strongly located; while in the ＂5.14＂ heavy rain process the radar echoes were widely convective-stratiform mixed echoes.