2008年7月23-24日山东暴雨天气过程分析

Analysis of the Rainstorm Weather Process in Shandong Province on July 23-24, 2008

利用常规气象资料、物理量场资料、卫星云图、大气监测自动站等资料，对2008年7月23-24日出现在山东中东部的暴雨天气过程成因进行了诊断分析。结果表明：暴雨天气过程是副高边缘的西南暖湿气流、西南涡和地面倒槽共同影响造成的；副高在暴雨预报中非常关键，副高的强弱影响暴雨的落区；低空急流向暴雨区源源不断地输送水汽，为强对流的发展积累了不稳定能量；850hPaθse的水平变化、能量锋区和6h降水区分布关系密切，高层引导气流对低层的引导作用较大，加强对500hPa形势场的维持和变化分析，有利于准确预报低层影响系统的发展和变化；本次过程降水存在明显的中尺度降水特征，地面辐合中心和辐合线为强降水发展提供了启动机制，强降雨中心位于地面辐合中心、辐合线附近。

By using the conventional meteorological data, the physical quantity field data, the satellite image and the data from the Atmospheric Automatic Monitoring Station, this paper diagnoses and analyzes the cause of the rainstorm weather process occurring in Mid-east Shandong on July 23 -24, 2008. According to the analysis, the rainstorm weather process resulted from the common influence of the southwest warm and wet flow on the edge of the subtropical high, the southwest vortex and the ground inverse trough. The subtropical high is critical in the forecast of rainstorm and its intensity influences the falling area of rainstorm. The low-level jet accumulated the unstable energy for the development of the severe convection by transporting vapor continuously to the heavy rain area. The horizontal variation of 850 hPa θse and the energy frontal zone have a close relation with the 6 h precipitation area distribution and the up- per layer plays a bigger role than the lower layer in leading the airflow. Strengthening the analysis of the maintenance and changes of 500 hPa situation field is beneficial to the accurate forecast of the development and changes of the system under the influence of the lower layer. In this process, an obvious feature of mesoscale precipitation existed, and the ground convergence center and the convergence line provided the starting mechanism for the development of the strong precipitation whose center was located near the ground convergence center and the convergence line.