中文摘要：

采用WRF中尺度模式,对2014年6月21—22日发生在江西省的一次连续暴雨天气过程进行了数值模拟,对模式输出的物理量进行了诊断分析,并开展了江西省东北部复杂地形的敏感性试验。结果表明：1）此次暴雨天气过程是建立在低空切变线和低空急流等系统基础上的一次降水。低空急流向暴雨区输送水汽和不稳定能量,低空切变线上中尺度系统活跃,造成强烈的上升运动,θse的垂直分布结构有利于中低层气旋的发展,不稳定能量的释放是暴雨发生和维持的机制之一。2）地形对这次暴雨的强度有很大影响。武夷山脉阻挡了切变线的南压。当武夷山脉存在时,山脉北侧在西南风环境中为迎风坡（以辐合为主）,山脉以南在西南风环境中为背风坡（以辐散为主）。移除武夷山脉后,其北侧和东北侧辐合减弱,南侧辐散减弱。武夷山主峰附近（117.6°E）的经向环流也表明,山脉移除后,主峰北侧（浙赣铁路沿线附近）的上升运动减弱,最终致使该地区降水减弱。

英文摘要：

The heavy rainfall process occurred in 21-22 June 2014 i n Jiangxi was simulated by the WRF mesoscale numerical model. Diagnoses were made based on the output data,and the influence of topography was analyzed. The conclusions were as follows：1）the precipitation was associated with low-level wind shear and low-level jet. The low-level jet transported water vapor and potential instable energy to the rainstorm areas,while active mesoscale systems on low-level wind shear triggered strong upward movement. The vertical structure of θsewas found favorable to the development of vorticity at low level,and the release of potential instable energy resulted in the genesis and maintenance of rainstorm. 2） The topography showed great effect on the strength of rainstorm,Wuyi Mountain prevented low-level wind shear moving southward. If Wuyi Mountain was removed,which would lead weaker convergence on the north and northeast side and upward motion and weaker precipitation along Zhejiang-Jiangxi railway.