Peak factor estimation in hurricane surface winds

The peak factor is a critical parameter in estimating short duration peak gust speeds. An analysis of sixty-four 10 m wind field records measured during the 1999-2008 Atlantic hurricane seasons shows a mildly positive non-Gaussian trend in the skewness of velocity with increasing longitudinal turbulence intensity (I-u). Kurtosis values exhibit slightly platykurtic behavior (kurtosis values less than 3) in open exposure but trend toward Gaussian as I-u increases. Average peak factors are computed from the data, stratified by wind speed and turbulence regime. Gust factor models are also examined; differences between the theoretical and observed zero up-crossing rates and power spectral density functions are used to discuss uncertainty propagation in the model. The results indicate that a non-Gaussian peak factor in theoretical peak gust (or gust factor) calculation appears to be warranted. Additional field measurements in built-up terrain are required to validate this finding. Published by Elsevier Ltd.