Estimating uncertainties from high resolution simulations of extreme wind storms and consequences for impacts

A simple method is presented designed to assess uncertainties from dynamical of regional high impact weather. The approach makes use of the that the choice of the simulation domain for the regional model is to a degree arbitrary. Thus, a small ensemble of equally valid simulations be produced from the same driving model output by shifting the domain by a of grid cells. Applying the approach to extra-tropical storm systems the simulations differ with respect to the exact location and severity of wind speeds. Based on an integrated storm severity measure, the ensemble members are found to vary by more than 25 % from the mean in the majority of episodes considered. Estimates of insured based on individual regional simulations and integrated over Germany differ by more than 50 % from the ensemble mean in most cases. Based on a of intense storm episodes, a quantification of winter storm losses under and future climate is made. Using this domain shift ensemble approach, ranges are derived representing the uncertainty inherent to the downscaling method.