【摘要】 利用常规天气图和１ｈ雨量图，分析了“９８·６”广西特大致洪暴雨过程的环流背景和中尺度系统，指出比常年偏南的西太平洋副热带高压、稳定的乌拉尔阻塞高压和南亚高压是极有利于中尺度系统在广西境内活动的环流背景，锋面上的扰动、西南低涡、西南热低压、西南低空急流等从区外移入广西的中尺度系统和海南岛绕流辐合、东兰和昭平附近的地形性涡旋和辐合等在本地特定地形条件下形成的地方性中尺度系统共同作用下产生了这次特大的致洪暴雨过程。当有利于中尺度系统活动的背景环流发生调整后，降雨过程便告结束。更多还原

【Abstract】 Based On Conventional synoptic chart and every othet an hour Precipitation chart, circu- lation background and miso-scal system of guangxi "98.6" exceptional flood-producing rainfall pro- cess was analysed. Result Showed that the background circulation, which was propitious to activi- ty of meso-scale system in Guangxi province, was composed by the south-deflection position of western pacific subtropical high、the stability of Ural block high and southern asian high. meso- scale systems such as frontal disturdance、south-western depression、south-western low-level jet、 south-western thermal depression that moved to guangxi area、and diffractive flow convergence caused by Hainan island, the meso-scale system caused by terrain vortex and convergence near Donglan and Zhaoping, were main cause of this exceptionalrainfall by interplay. The precipitation process was over after the adjustment of background circulation that propitious to activity of meso- scale system.更多还原