Gust Factors in Aerodrome Weather and Climate Assessment

Wind gustiness at airports is impactful in a range of considerations from piloting to airport planning. Impactful gusts can occur in significant weather systems, such as convective systems and mountain windstorms, but are also driven by mechanical turbulence in association with the built or natural environment. Aviation gust factors, based on the difference between the mean wind and peak wind, are used by aviators to address piloting. The meteorological community tends to address gustiness as a ratio between the peak wind and the mean wind as related to roughness impacts. Climatological assessments of both aviation gust factors and meteorological gust factors are conducted with 1-minute Automated Surface Observing System (ASOS) observations for multi-year periods at selected airports in the United States. Aviation gust factors and meteorological gust factors are demonstrated to vary significantly by direction at many airports and give different perspectives on gustiness due to prevailing winds and obstructions. The two gust factors are shown to be poorly correlated but become highly correlated when lower gusts are filtered out. Additionally, results for the situation in which the ASOS system was relocated provide context for siting impacts of weather observing systems and the robustness of the aviation gust factor.