An approach for the forecasting of wind strength tailored to routine observational daily wind gust data

Abstract

Daily wind gusts observed over Spain have been estimated by means of the statistical downscaling analogue model ANPAF developed by the authors. The model diagnoses large-scale atmospheric circulation patterns and subsequently estimates wind probabilities. Several data sets have been used: daily 1000 geopotential height (Z1000) field over the North Atlantic and the observational daily wind gust (WGU). Next, to give an additional value to the ERA-Interim wind gust data base (ERI), wind gust estimations from the analogue model were obtained to compare them with the wind gust data set from the ERA-Interim. The analogue method is based on finding in the historic geopotential height data base, a principal component subset of geopotential height patterns that are the most akin to a geopotential height pattern used as an input. Then, once the analogues are determined associated wind gusts are estimated from them. Finally, within validation stage are shown some results relative to the comparison between the wind gust estimated and ERI data. The probabilistic results are shown by means of Brier Skill Scores. The results show that the ANPAF model gives good wind gust information in the inner Iberian Peninsula and highlight that the Atlantic atmospheric patterns are, in general, better to predict gusts in such area. Though in only few stations the ANPAF model provides less additional value than the ERA-Interim data base for extreme wind gust values, the analogue model generally provides pretty information in estimating wind gust in Spain to the ERI data set.