【作者】 陈明轩； 高峰； 孔荣； 王迎春； 王建捷； 谭晓光； 肖现； 张文龙； 王令； 丁青兰；

【Author】 Chen Mingxuan1) Gao Feng1) Kong Rong1) Wang Yingchun2) Wang Jianjie2) Tan Xiaoguang1) Xiao Xian1) Zhang Wenlong1) Wang Ling3) Ding Qinglan3) 1) (Institute of Urban Meteorology, CMA, Beijing 100089) 2) (Beijing Meteorological Bureau, Beijing 100089) 3) (Beijing Weather Forecast Office, Beijing 100089)

【机构】 中国气象局北京城市气象研究所； 北京市气象局； 北京市气象台；

【摘要】 本文介绍了对流风暴自动临近预报系统(BJ-ANC)及其在2008年奥运期间的应用。BJ-ANC是在技术引进的基础上,通过本地化改进和拓展研发而形成的适合于在京津冀使用的对流风暴自动临近预报系统。系统通过多种风暴分析和临近预报算法,并利用模糊逻辑集成技术,产生反映风暴发生、发展和消亡的分析和预报产品。系统考虑了京津冀的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2008年实时预报结果的检验表明,系统对风暴单体在1h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1hQPF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。更多还原

【Abstract】 The system for auto-nowcasting 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 U.S.. The skill of the system is focused on nowcasting convective storm in Beijing and its vicinity. These main improved and developed algorithms include 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. Many forecast factors that produced by the above algorithms have very close relationship with initiation, evolution and decay of convective storm and has been integrated by a fuzzy logic algorithm under non-dimensionalized modes with different weighing coefficients in the system. And many storm analysis and nowcasting products has been formed that can indicate initiation, evolution and decay of convective storm and precipitation. Based on many studies and experiments, 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 ran in real-time mode during 2008 summer time. The system performance for nowcasting initiation and rapid evolution of storm was improved because convergence line was imported into the system by the interactive human entry function. Verification of storm cell extrapolation and 1-h QPF that available in Beijing area and its vicinity during 2008 summer are performed by using the B08FDP’s real-time verification system. The verification results indicate extrapolation of storm cell in 1 hour is significant and has small distance error contrasted with observed storm cell. The 1-h QPF from the system is comparable with rainfall observation from AWSs that denotes the QPF products can be used for supporting nowcasting operation of convective rainstorm. The validation of storm reflectivity nowcasts from the system are calculated and indicates reflectivity nowcasts are much more significant than those from persistence method. Storm case analyses indicate these products from the system are significant for supporting storm nowcasting operation and boundary layer convergence line has very close relationship with storm initiation and evolution. In addition, retrieval of thermo-dynamical fields can clearly indicate three dimensional structures of wind, convergence and temperature at low layer and further help forecasters make decision of storm initiation and evolution nowcasts.更多还原