相似环流背景下2次暴雨过程对比分析

为了提高抚顺地区暴雨短期预报能力，利用自动站观测资料、探空资料及NCEP再分析资料，对2013年7月9日和2013年8月16日抚顺地区暴雨天气过程进行对比分析。结果表明，2次过程均发生在偏西气流的纬向环流形势下，500 hPa贝加尔湖冷空气东南移是造成抚顺地区暴雨的主要影响系统。但不同点在于冷空气的输送形式，“07.9”暴雨过程是由贝加尔湖脊向东南方向移动导致，“8.16”暴雨过程主要是贝加尔湖脊前横槽南下所致。2次过程200 hPa均存在强盛的高空急流，但分流区的位置不同，“8.16”暴雨过程高空急流分流从辽宁西边界开始，从而有利于强暴雨的发生。低空急流、高空急流分流区的位置以及地面系统不同是导致2次暴雨强度差异的直接原因。

Comparative Analysis of Two Rainstorm Processes in the Similar Circulation Background

The paper aims to improve the short-term forecasting capability of rainstorm in Fushun. The author used automatic stations’ observation data, radiosonde data and NCEP reanalysis data, analyzed the rainstorm process on July 9, 2013 and August 16, 2013 in Fushun. The results showed that the two events occurred in the zonal westerly airflow circulation pattern, the cold air of Lake Baikal at 500 hPa which moved to the southeast was the main cause of rainstorm in Fushun Region. But the difference was the cold air delivery form, "07.9" rainstorm was caused by the southeastward ridge from Lake Baikal, "8.16" torrential rain process was mainly caused by horizontal trough from Lake Baikal. There was a very strong upper-level jet stream at 200 hPa in the two rainstorm processes, but their upper-level jet stream diversion district positions were different. The jet stream diversion of "8.16" torrential rain process began from the western boundary in Liaoning, thus contributing to the occurrence of torrential rain. Low-level jet, diversion district position of upper-level jet stream and ground system were the direct causes of the rainstorm intensity difference.