Brief Introduction of Operational Convection‐Allowing Ensemble Prediction System of North China

Spurred by technological advances, major operational centers and scientific research institutions have developed convection‐allowing ensemble prediction technologies and systems. To meet the demand for accurate localized severe weather forecasting, the convection‐allowing ensemble prediction system of North China (CMA‐BJ‐EN), developed by the Institute of Urban Meteorology, China Meteorological Administration (CMA), became officially operational in January 2023. This paper provides a comprehensive introduction to the system's research and development background and key technologies. The CMA‐BJ‐EN system has a convection permitting grid spacing of 3 km, covering 21 members, and can provide hourly probability prediction results of 48 h forecasts over North China. The system is coupled with technologies such as ensemble of data assimilations, Stochastically Perturbed Parameter Tendencies (SPPT), and has complete operational configuration. The qualitative and quantitative evaluation of the CMA‐BJ‐EN system and its comparison with the NCEP global ensemble forecast system show that the system can effectively forecast several major weather events in North China and can obtain local refined probability forecast results relative to global ensemble. The statistical results also show that compared with the NCEP global ensemble forecast, the CMA‐BJ‐EN system can effectively reduce the RMSE of 2 m temperature and 10 m wind speed and can improve the AROC score of precipitation forecast by 5%–10% for heavy rainfall. The operation of the system can provide users with effective refined probability forecast reference.