Sensitivity Studies for a Hybrid Numerical-Statistical Short-Term Wind and Gust Forecast at Three Locations in the Basque Country (Spain)

This study evaluates the performance of statistical models applied to the output of numerical models for short-term (1-24 h) hourly wind forecasts at three locations in the Basque Country. The target variables are horizontal wind components and the maximum wind gust at 3 h intervals. Statistical approaches such as persistence, analogues, linear regression, and random forest (RF) are used. The verification statistics used are coefficient of determination (R-2) and root mean square error (RMSE). Statistical models use three inputs: (1) Local wind observations; (2) extended EOFs (empirical orthogonal functions) derived from past local observations and ERA-Interim variables in a previous 24-h period covering a domain around the area of study; and (3) wind forecasts provided by ERA-Interim. Results indicate that, for horizons less than 1-4 h, persistence is the best model. For longer predictions, RF provides the best forecasts. For horizontal components at 4-24 h horizons, RF slightly outperformed ERA-Interim wind forecasts. For gust, RF performs better than ERA-Interim for all the horizons. Persistence is the most influential factor for 2-5 h. Beyond this horizon, predictors from the ERA-Interim wind forecasts led the contribution. Hybrid numerical-statistical methods can be used to improve short-term wind forecasts.