台风倒槽影响下邯郸大暴雨过程分析

从天气系统背景、FY-2C卫星产品、水汽通量分布特征和大气稳定度特征等方面,分析了受台风低压倒槽与东移锋面云系的共同影响,于2005年7月21日夜间到23日邯郸市出现的大范围的暴雨天气,结果发现:500hPa槽前中尺度切变线是直接影响产生暴雨的重要系统;地形作用使迎风坡降水增强;中尺度对流云团和雨团关系密切,暴雨中心位于OLR和TBB低值区下面;西部山区的暴雨区水汽主要来源于南海、东海,东部平原大暴雨水汽主要来源于南海;暴雨区上空低层为对流不稳定,高层为对称不稳定。

Effect of Inverted Trough on Heavy Rainfall Process of Handan

Utilizing synoptic features,FY-2C satellite product,characteristics of water vapour transportation and stratification features,we analyze the heavy rainfall by inverted trough and eastward propagating frontal systems appear in Handan from the evening of July 21 to the morning of July 23,2005.The results show that the mesoscale shears line lying in front of 500 hPa trough played an important role during the heavy rainfall events.Orographic lifting enhanced the precipitation.Mesoscale convective cloud is related closely with rainmass.The heavy rainfall area is located under the lower total ozone of OLR and TBB.The water vapour supply of the heavy rainfall in the western part of Handan is mainly from South China Sea and East China Sea,while the supply in the eastern from South China Sea.Convective instability at low level and symmetric instability at high level are the mechanism of heavy rainfall.