Seasonal bias-correction of daily precipitation over France using a stitch model designed for robust extremes representation

Abstract: Highly resoluted and accurate daily precipitation data are required for impact models to perform adequately and to correctly measure high-risk events' impact. In order to produce such data, bias-correction is often needed. Most of those statistical methods correct the probability distributions of daily precipitation by modeling them using either empirical or parametric distributions. A recent semi-parametric model based on a penalized Berk-Jones (BJ) statistical test which allows for an automatic and personalized splicing of parametric and nonparametric has been developed. This method, called Stitch-BJ model, was found to be able to model daily precipitation correctly and showed interesting potential in a bias-correction setting. In the present study, we will consolidate these results by taking into account the seasonal properties of daily precipitation in an out-of-sample context, and by considering dry days probabilities in our methodology. We evaluate the performance of the Stitch-BJ method in this seasonal bias-correction setting against more classical models such as the Gamma, Exponentiated Weibull (ExpW), Extended Generalized Pareto (EGP) or empirical distributions. The Stitch-BJ distribution was able to consistently perform as well or better than all the other models over the validation set, including the empirical distribution, which is often used due to its robustness.