青海省东部一次副热带高压东退型强降水过程分析

TheAnalysis of a Heavy Rainfall Caused by the Eastward Retreat of Subtropical High over the Eastern Qinghai

利用常规气象资料对2007年8月25日青海省东部的大到暴雨过程进行了诊断分析。研究表明:此次过程是由于500hPa副热带高压东退、高空短波槽东移引导冷空气南下,冷暖空气在青海省东部交汇造成的一次对流性强降水天气;此次降水过程中西南、偏南和偏西路径的三条水汽通道在青海省东部汇合;青海省大降水多出现在东部地区,这与青海省东部河谷地形的抬升和辐合作用以及中小尺度系统活动密切相关。

Utilizing the conventional meteorological data,the heavy rain in eastern Qinghai on August 25, 2007 were diagnosed and analyzed. The results show that the process is a convective heavy precipitation weather caused by the retreat of 500hPa subtropical high eastward, the eastward movement of high altitude short wave trough to guide cold air southward and the convergence of cold and warm air in the eastern part of Qinghai Province;the convergence of three water vapor channels along the southwest, South and West paths in the eastern part of Qinghai Province during the precipitation process;the heavy precipitation in Qinghai Province mostly occurs in the eastern part, which is in line with Qinghai Province. The uplift and convergence of the eastern valley topography are closely related to the activities of meso-and small-scale systems.