【摘要】 利用 2 0 0 1年 9月 17～ 2 1日T10 6客观分析资料 ,较详细地分析了“9 18”四川盆地西北部大暴雨过程的物理条件和可能机制 ,发现向北推进的低空偏南风急流促使川西北形成有利于暴雨的热力、水汽和动力条件。低空急流最大风速出口辐合上升区与地形抬升作用共同造成盆地西北强烈的垂直上升运动 ,激发对流云团强烈发展 ,是本次暴雨的触发条件。局地地形的强烈抬升作用增强了上升运动和水汽辐合 ,对暴雨产生了较强的增幅作用更多还原

【Abstract】 Based on the T106 objective analysis data obtained from 17 to 21 September of 2001,the physical conditions and possible mechanism of Sichuan ″9.18″ torrential rain are analyzed. The results reveal that northward low level south east jet would cause favorable thermodynamic, moisture and dynamic conditions for the heavy rainfall in the northwestern Sichuan. The strong upward vertical movement, resulted from the convergence ascending of low level south east jet exit region and the local topographic forcing, stimulated strong convective clouds. The heavy rain was amplified to a great extent by local topographic forcing, and the convergence of low level wet air.更多还原