PNNL

Abstract

The primary goal of the second Wind Forecast Improvement Project (WFIP2) is to advance the state of the art of wind energy forecasting in complex terrain. To accomplish this task, an 18-month observational field campaign was conducted to capture a rich sampling of complex orographic flows in the region of the Columbia River Basin. The multiscale and multivariate set of observations has been used to improve the understanding of meteorological processes associated with the primary weather events that modulate wind energy in the region. The observations were used to diagnose and quantify systematic forecast errors in the operational High-Resolution Rapid Refresh (HRRR) model associated with these weather events. Furthermore, the observations were used to facilitate the attribution of these errors to deficiencies in particular model parameterizations. WFIP2 model development has focused on the boundary-layer and surface-layer schemes, cloud–radiation interaction, the representation of drag associated with subgrid-scale topography, and the representation of wind farms in the HRRR. Additionally, investigating the effects of horizontal (and three-dimensional) mixing and refined numerical methods has also helped improve some of the common forecast error modes. This study describes the model development and testing undertaken during WFIP2, and demonstrates the forecast improvements achieved from this effort, drawing upon case studies and long-term retrospective experiments. The model improvements made in WFIP2 are also shown to be applicable to regions outside of complex terrain. Ongoing and future challenges in model development will also be discussed.