Boundary-Layer Wind-Flow Variability in Complex Terrain from Scanning Doppler Lidars and NWP Operational Models

Wind-flow variability through the lowest several hundred meters of the atmosphere is analyzed from Doppler lidar measurements at three sites in the Columbia River Basin during the second Wind Forecast Improvement Project (WFIP-2). The variability is assessed at different time-scales from daily cycles to seasonal and yearly variations. In addition to quantifying the temporal and vertical variability of wind flows at each site, analysis of measurements from the three lidars, which were separated by less than 40 km along a 70-km line oriented roughly along the prevalent west-east wind directions in the Basin, provide a unique opportunity to understand the horizontal wind variability among these sites due to the complex terrain and the overall modification of wind flows by the local wind farms in the area. High-vertical resolution lidar data allow detailed analysis of wind flows at turbine hub height and within the turbine rotor layer and also allow evaluation of the ability of the High-Resolution Rapid Refresh (HRRR) and Rapid Refresh (RAP) operational models to simulate these flows under various meteorological conditions and for periods of interesting meteorological events observed in the study area. Validation metrics such as bias, RMSE, MAE, and the correlation coefficient between observed and modeled wind variables, analyzed as a function of height, time, and forecast lead hour, address how well the models replicate the spatial and seasonal variability of the wind profiles and provide insight into potential model improvements.