该文介绍了对流风暴自动临近预报系统（BJ-ANC）及其在2008年北京奥运会期间的应用。BJ-ANC是在技术引进基础上,通过本地化改进和拓展研发而形成的适合于在京津冀地区使用的对流风暴自动临近预报系统。BJ-ANC系统通过对风暴进行分析,利用临近预报算法和模糊逻辑集成技术,生成反映风暴发生、发展和消亡的分析及预报产品。系统考虑了京津冀地区边界层辐合线及地形与风暴生消发展之间的密切关系。通过对2008年实时预报结果的检验表明：系统对风暴单体在1 h内的外推预报与实际观测的风暴单体中心的距离偏差较小;系统的1 h定量降水预报和自动站的降水观测接近;系统对风暴回波的总体预报性能明显优于持续性外推方法。通过对2008年奥运期间对流风暴个例的实际应用分析表明：系统对风暴的临近预报具有指导意义,边界层辐合线对风暴的局地新生和快速演变具有明显的正面预报效果。另外,系统反演得到的对流层低层热动力三维特征提供了风暴生消、发展预报的重要判据。
The auto-nowcasting system for convective storm（BJ-ANC） is an expert system that has been improved and further developed to many key algorithms and modules other than they are just introduced from US.The skill of the system is focused on nowcasting convective storm in Beijing and its vicinity.Key improvements have been made to the algorithms including quality control of CINRAD radar data,diagnosis and analysis of local observations from radars,satellites,AWSs,rawinsondes and meso-NWP results from a WRF-based rapid update cycling model,identification,analysis and tracking of storm cells,grid-tracking and extrapolation of radar echo,rapid updating assimilation of radar data,quantitative precipitation estimate （QPE） and quantitative precipitation forecasting（QPF）,etc. The forecast factors produced by the above algorithms are closely related with initiation,evolution and decay of convective storm in general.These algorithms are integrated by a fuzzy logic algorithm under non-dimensional modes with different weighting coefficients in the system and nowcasting products are generated. Based on many theoretical and experimental results,the relationship and conceptual model of boundary layer convergence line and initiation and evolution of storm have been imported into the system for nowcasting localized initiation and rapid evolution of storm. BJ-ANC system runs in real-time mode during 2008 summer time.The system performance for nowcasting initiation and rapid evolution of storm is improved after convergence line is adopted by interactive human entry function.Verification of storm cell extrapolation and 1-hour QPF in Beijing area and its vicinity during 2008 summer is performed using the B08FDP real-time verification system.The results indicate extrapolation of storm cell in 1 hour is significant and the forecast deviation is small.The 1-hour QPF from the system is comparable with rainfall observation from AWSs,denoting the QPF products can be used for supporting nowcasting operation of convective rainstorm.
Quarterly Journal of Applied Meteorology