A 99-Day Assessment of the Weather Research and Forecasting Model over the Southwest United States, Volume 2: Spatial Distribution of Verification Scores

An assessment was conducted over a 99-day period during winter over complex terrain to evaluate the accuracy of forecasts produced by the Advanced Research version of the Weather Research and Forecasting model (WRF-ARW). The Army Weather Running Estimate-Nowcast Real-Time (WREN_RT) system is a scripted system that provides forecasts by executing WRF-ARW and its preprocessors used to produce the WRF-ARW forecasts for this study. WREN_RT aims to provide forecasts for ingestion into decision aids that produce knowledge products for Warfighters. These products include the 2-D distribution of weather phenomena that can impact Army missions and systems. The traditional categorical method of spatial verification was used on the WRF output and ground truth data to compute skill scores for a range of neighborhood sizes and thresholds. The scores were computed and aggregated over the entire model domain to show how they are affected by terrain features. For ground truth data, gridded observations from the UnRestricted Mesoscale Analysis were used. The results of the assessment showed that WRF scored very well over some terrain features and land surface types and not so well over others.