Improving the Meiyu Simulation Using Spectral Nudging of SingleElement and MultiElement in HighResolution Regional Numerical Model
This paper reviews the development of the technology for seamless fine gridded weather forecasting in China since 2014. And the key technical difficulties in the future development are analyzed. It is pointed out that the high spatiotemporal resolution observations capturing the fine structure of weather systems, the analysis products by multisource data fusion, the realtime rapid updating assimilation and prediction system, the high resolution regional model providing shorttime and shortterm weather prediction, the global numerical forecast model providing 10 days’ weather forecasting, and the oceanatmosphere coupled ensemble prediction system providing 46 days’ weather prediction, have jointly established the premise and foundation of the seamless gridded weather forecasts. After nearly 5 years’ exploration and constant efforts, the technology system of seamless fine gridded forecasting with different temporal resolutions has been established. The highfrequency lagrangian extrapolation skills are used for 0-4 h forecasting based on GRAPESMeso model forecast products and radar data over China. For the 4 h to 30 d leadtime forecasting, it mainly depends on the downscaling, error correction, model output statistics and postprocessing methodologies based on regional and global models of different spatiotemporal resolutions to improve forecast skills and resolution. At the same time, automatic and intelligent interactive forecasting platform is developed to meet the demand of combining efficient objective forecasting with forecasters’ subjective intelligence. In order to assess and track the performance of high resolution gridded forecasting, a spatial analysis verification method based on gridded observation data is developed. It is also stressed that the future gridded forecasting technology system should be able to reflect the latest technology development including the artificial intelligence application, more advanced statistical postprocessing skills, key technics for consistency forecasting and unified complete technical architecture and standards.