Analysis of Local Torrential Rain Caused by the Hollow Typhoon “Matmo”
Guo Dafeng;Bao Huimeng;Zhou Fang;Zheng Jing;Jiangxi Provincial Meteorological Observatory;
Using conventional weather data, NCEP reanalysis data and Nanchang Doppler radar data, the hollow structure of typhoon "Matmo" after its landing and local torrential rainfall occurred on July 24 2014 over De′an county in Jiangxi Province are analyzed in terms of circulation characteristics, vapor condition and the intrusion of cold air. The results showed that the hollow structure of typhoon "Matmo" was caused by the change of high-level divergence flow field from south Asia easterly jet, the underlying surface and the topography. The interactions between the cold air and the northeast circulation of typhoon greatly strengthened the atmosphere instability over De′an. The formation and maintenance of meso-scale convergence line led to intensify low-level convergence and strong convection. In addition, enough vapor convergence from easterly jet caused this heavy torrential rainfall.