2018年台风温比亚的强对流螺旋雨带观测特征分析

Characteristics Analysis on the Severe Convective Spiral Rainband of Typhoon Rumbia(2018)

利用中央气象台中尺度地面降水观测资料、气象雷达观测资料和NCEP FNL资料,以及中国气象局上海台风研究所台风最佳路径资料,研究了2018年台风温比亚深入内陆后造成华东地区强降水的雨带结构和演变特征及天气尺度背景环境。结果表明:"温比亚"登陆后的雨带在皖豫鲁交界和山东中南部两度表现为多条短螺旋雨带合并发展为单一长雨带的特征;雨带的维持和形态演变主要是"温比亚"台风环流和强度维持及其与副热带高压的停滞西伸加强的相互作用决定的;由于低层垂直风切变的加强,两条长雨带分别在其起端的安徽北部和山东南部两度表现出显著的对流特征,并都伴有龙卷的发生。

Based on densely-observed surface and radar data and NCEP FNL data as well as the best track data from Shanghai Typhoon Institute/CMA,this article examines the structure and evolution of the rainbands of Typhoon Rumbia that caused torrential rain in East China after Rumbia moved far into inland.The results show that the rainbands twice manifested evolutions from multiple short rainbands into a single long rainband respectively around the boundaries between Shandong,Henan and Anhui provinces as well as mid-southern Shandong Province.The maintenance and evolution of the rainbands were determined mainly by the sustaining of typhoon circulation and intensity and its interaction with the stagnation and westward extension of subtropical high.Because of the intensification of low-level vertical wind shear,the rainbands displayed apparent convective features with embedded tornadoes in northern Anhui and south Shandong.