0513号台风泰利异常强暴雨过程的综合分析

Analysis of Torrential Rain Event of Landing Typhoon Tailim

利用地面加密观测资料和NCEP再分析资料,对0513号台风泰利进入江西减弱成低气压引发的异常强暴雨过程进行了综合分析。结果表明:移进赣西北后,台风泰利减弱的低气压北部有明显的冷空气侵入,导致行星边界层能量锋区加强;华西地区大陆高压阻挡了台风低压西移,其北侧弱环境流场的配置为台风低压长时间停滞提供了有利的背景条件;低层稳定的水汽输送、中纬度冷锋前部的东北气流与来自低纬海洋上的东南气流在台风低压附近形成明显辐合有利于强暴雨过程的发展;异常强暴雨主要分布在大别山东麓和庐山九岭山脉迎风坡上,地形的抬升对暴雨增幅有明显作用。

A synthetic analysis of heavy rainfall event of typhoon Tailim depression in Jiangxi Province during 2-4 Sep. 2005 is made with the dense observational data and NCEP re-analysis data. The results show that the weak cold air invading to the typhoon depression led to the strength of energy front in PBL when the typhoon depression is steady in northwest of Jiangxi. The development of continental high in West China retarded the westward moving of typhoon depression. A weak environment stream field provided a good condition to its maintaining long time and staying in northwest of Jiangxi. The sustained vapor transport and divergence of NE cold current from the cold front in meddle latitude and SE warm flow from ocean in low latitude were helpful to the severe torrential rainfall event as the good dynamical and thermal conditions to the typhoon depression in low tropospheric levels. It was demonstrated that the orographic effect contributed greatly to precipitation enhancement due to orographic lifting and convergence with intensified precipitation on the windward slope of the Dabie mountains and Lushan mountain as well as Jiuling mountains.