【摘要】 本文利用复杂地形条件下嵌套网格预报模式和欧洲中心(ECMWF)2.5°×2.5°的全球网格点资料,对“81.7”四川大暴雨进行了单向影响粗细网格嵌套48小时的个例预报试验;并根据滤波原理,利用最佳高通滤波器,将风场、位势高度场和温度场进行了中尺度分离。结果表明:本模式较好地预报了造成这次暴雨的中尺度系统发生、发展的过程;并对动力和热力影响作了一些粗浅的分析,本模式较好地描述了暴雨天气,细网格预报在某些方面有进一步改进。该尺度分离方法也能在扰动发展的早期阶段就能从大尺度背景场中将西南涡等中尺度系统清晰地分离出来,使我们能对影响这次暴雨的中尺度系统有进一步的认识。更多还原

【Abstract】 In this paper, we use a nested grid model under complex topography and ECMWF global data with resolution of 2.5°×2.5° grid size to perform 48 hour forecasting experiment of coarsemesh and fine-mesh for the case of "81.7" heavy rain in Sichuan province.According to the principle of filtering we separate the fields of wind, geopotential height and temperature using optimum high-pass filter.The results show that the model can fairly predict the generation and development of meso-scale system causing this heavy rain.We have also roughly analyzed the dynamic and thermal effects.This model can fairly described the weather of heavy rain.In the other hand, it is also showed that the fine-mesh forecasting has been made further improvement in some aspect.The scale separative method can clearly separate the vortex in the southwest of China and other meso-scale system from large scale foundational field and make us further to recognize the effect of the meso-scale system during the early stage of disturbance on this heavy rain.更多还原