一次短期集合预报试验

数值模式中物理过程描述不准确是造成数值预报误差的主要来源之一，采用数值模式中不同物理过程的集合预报方案是减小模式预报误差的有效方法。本文结合一个典型的夏季东北冷涡型降水天气过程，选用不同的积云对流参数化方案、显式降水方案、辐射方案以及模式采用不同的地表分辨率构成10集合预报成员，进行了48h的预报。结果显示集合预报在总体预报效果上比各个集合成员的预报效果好，简单的集合平均就可以提高模式形势场和降水要素场的预报准确率。在集合平均提高预报准确率的同时，采用天气系统移动路径图、面条图以及降水概率预报等方法，可以增强小概率事件的预报能力。

RESEARCH ON SHORT-TERM ENSEMBLE FORECAST

Error coming from treatment of physics processes is one of major reasons of numerical weather prediction errors, ensemble forecast is an effective way to diminish the errors. In this paper, 10 members' ensemble forecast scheme consists of five kinds of resolvable scale precipitation processes, two kinds of implicit cumulus parameterization schemes, two kinds of atmospheric radiation parameterization and one kind of terrain resolution, which was run to predict 48 hours' weather of a typical northeast cold vortex. The results show the results of ensemble forecast are better than that of each member's, the simple average of ensemble members' prediction results can improve forecast accuracy; at the same time, prediction accuracy of little probability case may be improved by analyzing moving route chart of weather system, characterized isolinechart and precipitation probability forecast chart.