2020年8月14—15日聊城极端降水过程成因分析

Cause Analysis of an Extreme Precipitation Process in Liaocheng from August 14 to 15,2020

【目的】通过研究聊城出现的一次极端降水过程,揭示天气成因,提升农业气象服务水平。【方法】从天气实况、环流背景和影响系统、雷达产品出发,对该次极端降水过程进行多尺度特征分析。【结果】低层大气有顺时针的垂直风切变,强暖平流,为此次聊城暴雨发生提供有利的水汽和能量供应,主要影响系统为副高边缘的西南急流和暖式切变线。通过雷达产品分析,聊城市在云顶亮温最低的中部地区,云团合并、亮温梯度最大的南部地区,产生短时强降水和暴雨天气。【结论】研究结果可为暴雨预报预测和相关研究提供参考依据。

[Purposes]To reveal the cause of this extreme precipitation and improve the level of agrome-teorological services by studying an extreme precipitation process in Liaocheng.[Methods]The multi-scale characteristics of the extreme precipitation process were analyzed based on the weather conditions,circulation background,impact system and radar products.[Findings]There was a clockwise vertical wind shear and strong warm advection in the lower atmosphere on the Tlogp map of Zhengzhou,which provided favorable water vapor and energy supply for the Liaocheng rainstorm;The main impact system of this heavy rainfall is the southwest jet and warm shear line at the edge of the subtropical high.Through the analysis of radar products,Liaocheng City produces short-term heavy rainfall and rainstorm weather in the central region with the lowest brightness temperature at the top of the cloud,and in the southern re-gion with the highest brightness temperature gradient due to the combination of cloud clusters.[Conclu-sions]The research results can provide some reference basis for rainstorm forecast and related research.