极端天气指数在强对流天气中的应用及检验

数值预报特别是集合预报技术大大提高了对极端天气的预报能力,目前对于温度、风、降水等要素,欧洲中心基于集合预报产品计算的极端指数产品为其极端性提供了定量化依据。但目前尚没有应用于业务预报的强对流天气极端指数产品,本文统计了与强对流天气密切相关的物理量,并计算了其极端天气指数,统计了极端天气指数在不同强对流天气中的阈值分布。结果表明,极端天气指数与强对流天气有密切的关系,且不同类型的强对流天气极端指数的分布和阈值具有各自的特点。基于上述结果,利用极端指数和模式降水资料,使用支持向量机方法,建立了不同类型强对流天气的客观预报方法,为业务预报极端强对流天气提供客观支持产品。

Application and verification of extreme forecast index in severe convection weather

Numerical forecasts, especially ensemble forecast techniques, greatly improve the ability to predict extreme weather. At present, for the temperature, wind, precipitation and other factors, the European Center''s extreme index products based on ensemble forecast products provide a quantitative basis for their extremity. However, there is currently no strong convective weather extreme index product for operational forecast. Therefore, this paper counts the physical quantities closely related to the strong convective weather, calculates its extreme weather index, and counts the threshold distribution of the extreme weather index in different severe convective weather. The results show that the extreme weather index is closely related to the strong convective weather, and the distribution and threshold of different types of strong convective weather extreme indices have their own characteristics. Based on the above results, using the extreme exponential and model precipitation data, using the support vector machine method, this paper establishes an objective forecasting method for different types of severe convective weather, and provides objective support products for operational forecast of extremely strong convective weather.