中文摘要：

暴雨是我国夏季多发的一种灾害性天气，每年都造成了不同程度的财产损失和人员伤亡。暴雨预报不仅是气象和水文预报人员所关心的问题，也是广大人民群众和各级领导十分关心的问题。许多重大的政治经济活动事先都必须考虑气象预报的结果，以便做出合理的决策。因此，暴雨等灾害性天气预报不仅仅是一个自然科学问题，也是一个社会科学问题。集合预报技术作为一种新兴的数值天气预报技术，针对数值预报的误差来源，采用合理的扰动原理和扰动方法，构造能沿着模式大气相空间最不稳定的方向快速增长的扰动场与集合预报成员，不仅大大提高了人们对暴雨等灾害性、转折性、突发性、局地性天气过程的认识和预报能力，更进一步将自然科学和社会科学紧密联系，使自然科学更好地解决社会生产生活问题，为各级领导和群众合理安排生产生活活动、抗御暴雨等灾害提供了有力的技术保障。

英文摘要：

Rainstorm is a kind of frequently disastrous weather process, and it often causes great casualty and economic losses each year. The accurate forecast of rainstorm is not only a scientific problem, but a social problem. The technique of ensemble forecast is a kind of newly developed numerical prediction method. It makes use of reasonable perturbation technique to produce a team of forecasting results, from which the reasonable probability forecast for momentous weather process, such as rainstorm and hurricanes can be gotten. It is also a linkage between social and natural science. Based on the theory of risk analysis, this paper presents a very good evaluation of future rainstorm analysis and a good confidence in arranging social production and activities.