The Development of Data Assimilation System for the Regional Rapid-Refresh Model within the Enterprise Integrated Aviation Weather System

A high-resolution Regional Rapid-Refresh modeling system is under development within the Enterprise Integrated Aviation Weather System (eIAWS^TM) en-Route service function (eIAWS-R3R), aimed at improving strategic air traffic management (ATM) decision-making. Current and future ATM requires more accurate short-range aviation weather forecasting. A data assimilation system is designed and developed for the eIAWS-R3R platform. The Gridpoint Statistical Interpolation (GSI) is used to assimilate various observations into the system, and the Non-hydrostatic Multiscale Model on the B-grid (NMMB) is used to provide high resolution forecast up to 9 hours.

eIAWS-R3R is designed to run with a 3-km horizontal resolution and assimilate conventional and unconventional observations hourly, using limited computing resources. This requires that the system has capability to capture and initialize convective storms in a timely manner. Data assimilation methods and strategies are explored. Initial performance test results are compared and discussed based on both forecasting skills and computational costs.