Sensitivity and Accuracy of Sundowner Wind Forecasts

Sundowners are a downslope wind phenomenon that occurs in and near Santa Barbara, California. We have evaluated the performance of operational and research forecasts of Sundowner events. The operational models considered include the 3-km North American Mesoscale (NAM) and High Resolution Rapid Refresh (HRRR) and research simulations employed the Weather Research and Forecasting (WRF) Advanced Research WRF core, initialized with NAM and HRRR outputs. Data used in verification include standard surface stations as well as observations collected during the SWEX 2020 campaign, which was scaled back owing to the coronavirus. Preliminary results indicate that the HRRR struggles with developing Sundowner winds when compared to NAM and even WRF simulations initialized with HRRR. An explanation for this curious behavior will be discussed.