Storm Models for the Calculation of Extreme Wind Speed

Abstract This paper proposes a new approach for the calculation of extreme wind speed. Specifically, the storm approach widely employed for long-term statistics of ocean storms is reviewed and adapted for the analysis of windstorms. This approach is based on the substitution of the sequence of real event at a given site with a sequence of simplified events characterized by a kind of equivalence with the actual ones. Basing on that, analytical solution for the calculation of the return period of a storm event whose peak exceeds a given threshold is developed. The windstorm model characterizes the simplified windstorm event by means of two parameters which are the maximum average wind speed over the windstorm and a duration parameter determined by imposing that the maximum expected gust in the simplified event is the same of that in the actual one. First, an attempt is made to assimilate the peak gust to a “maximum expected gust” and to relate this quantity to the windstorm duration. Then, in order to validate the new model, a data analysis is carried out to estimate average wind speed return values with the proposed approach and results are compared with those provided by well-established peak over threshold method.