Comparative Analysis on Extraordinary Heavy Rainfall Caused by Inverted Trough of Typhoon

ZHENG Feng (Chinese Academy of Meteorological Science,Beijing 100081)

Extraordinary heavy rain;Inverted trough of typhoon;Weak cold air

Taking the significant inverted trough difference between the extraordinary heavy rain caused by the inverted trough of 8712 typhoon with cold air invasion and medium rain only occurred in Wenzhou of the inverted trough of 6122 typhoon as an example,the reasons caused the extraordinary heavy rain of the interaction effect between cold air and inverted trough of typhoon in Wenzhou were discussed by using the dynamic and thermal physical quantities such as humidity,Q vector divergence and latent heat.And it was compared with the physical quantity field in the inverted trough without cold air invasion to probe into the inner reasons for greater rainfall difference of typhoon inverted trough.It was found that typhoons landed from south of Xiamen to east of Guangdong formed the inverted trough of typhoon on the southeastern coast of Zhejiang.Weak dry cold air in lower levels in autumn was easy to invade into the inverted trough of typhoon and interact with the strongly warm and wet advection so as to strength the baroclinic pressure.Unstable energy release was the important reason that caused the extraordinary heavy rain of the inverted trough.