Battlescale Forecast Model (BFM) During the TFXXI at Fort Irwin, CA: Statistical Evaluation of 24 h Forecast Fields and Model Improvement

摘要

The U.S. Army's Battlescale Forecast Model (BFM) was operationally used for forecasting surface meteorological parameters during the Department of Defense (DOD) Task Force XXI exercise which was held at the National Training Center (NTC), Ft. Irwin, CA, in March 1991. The results of the BFM forecast calculstions were unsatisfactory, primarily due to the following physical and numerical shortcomings in the model operation: scarcity of input meteorologicsl data, poor selections of surface albedo and soil heat conductivity values, nudging method used to assimilate large scale meteorological data dominating the solutions of the equations of motion. After the exercise, an attempt was made to improve the model's performance. Forecast data, obtained by using different input and boundary condition data and an improved model numerical scheme, were statistically compared with surface automated data collected at the NTC during March 1997. Using the updated numerics in addition to an upgraded grid distribution of the Navy Operational Global Atmospheric system (NOGAPS) forecast data from 2.5 to 1 deg resolution (used to provide the large scale forcing for the BFM) resulted in a substantial improvement in the model's forecast skill.