On the problems and challenges in regional OSSEs

Recently, there has been substantially increased interest in the observing system simulation experiments (OSSEs) in conjunction with the instrumentation development. In many past studies, the OSSEs were mainly done by major operational centers with global models. However, many needs in improving mesoscale and regional weather forecasting make it necessary to use the regional model to assess the impact of the future instruments on the forecast of mesoscale weather systems, especially high-impact weather systems (such as hurricanes, frontal systems etc.). In this presentation, the necessity of the regional OSSEs, common methodologies, challenges and potential development are discussed with numerical results from the mesoscale community weather research and forecasting (WRF) model and its data assimilation systems. The evaluation of ECMWF nature runs for regional OSSEs, and the potential impact of the future Doppler lidar wind on hurricane intensity forecasts assessed from the regional OSSEs are also presented.