2011年9月运城连阴雨中暴雨天气成因分析

Weather Cause Analysis of Rainstorm in Yuncheng Continuous Rain in September 2011

本文利用常规高空及地面观测资料、Micaps资料及自动站降水资料，使用天气学诊断方法，对2011年9月9日-13日出现在运城连阴雨中的暴雨过程进行了综合分析。结果表明，西风槽、副高、700hPa切变线是这次连阴雨中暴雨过程的主要影响系统。低空急流为此次降水提供了充足的水汽输送，其水汽主要来源于孟加拉湾。暴雨维持时间基本和高层比湿峰值及低层谷值维持时间相对应，高层比湿峰值的出现预示强降水时段的开始。暴雨上空具有高层强辐散、低层弱辐合的散度结构和较强的上升运动，但其数值明显偏小，表明秋季连阴雨中暴雨对流强度不如盛夏暴雨。

Using the sounding, surface observation data, Micaps data and automatic station data, the rainstorm process in continuous rain was comprehensive analyzed on September 9 to 13, 2011. The results showed that the westerly trough, the subtropical high and 700hPa shear line was affecting the system of the continuous rain. Low-level jet provided sufficient water vapor transportation for the continuous rain. Water vapor came mainly from Bay of Bengal. Duration of rainstorm corresponded to the high level specific humidity max value and low level specific humidity min value. The convection intensity of rainstorm in continuous rain in autumn was not stronger than in summer.