Development of RMAPS model system for urban multi-hazard prediction and warning

Adhering to the long-term goal of improving the accuracy of 0-24 hour fine-scale numerical weather forecasting for urban areas, we developed the Rapid-update Multi-scale Analysis and Prediction System (RMAPS) that coupled physical and chemical processes such as urban land surface and aerosols, achieving seamless analysis and prediction within 0-24 hours, 10-minute updates, and 10-meter grid spacing objective analysis and prediction. RMAPS model system includes urban short-term numerical weather forecasting (ST), environmental meteorological forecasting, integrated forecasting, large eddy simulation, and urban micro-scale forecasting (URBAN), etc. RMAPS-ST with horizontal grid spacing of 333-meter are developed, including data assimilation of dense observations and multi-layer urban canopy model. RMAPS-URBAN with horizontal grid spacing of 10-meter includes wind field rapid diagnosis model, hydro-thermal processes, human comfort model, and pollution diffusion model. Rainstorm disaster risk assessment and early warning model has been developed to realize real-time risk forecasting. A comprehensive index for meteorological and environmental impacts on health is proposed. RMAPS model outputs are used to drive urban multi-hazard prediction and warning, including heatwave, waterlogging, air quality, health, etc. RMAPS model system has provided very good meteorological support for urban management and many national major events such as Beijing 2022 Winter Olympics. Recent developments and open challenges will be discussed.