On the estimation of extreme wind gusts by direction sector

For economic design of large structures it would be desirable to have maximum wind gust estimates for each direction sector rather than the global estimates at present available. Current observational practice is to record only a single maximum gust daily, together with its direction sector, for each observing station. These data could be used to make directional estimates of extreme gusts only if no significant gusts from any direction are masked by stronger gusts from other directions on the same day. To obtain an indication of whether such masking occurs, twenty-nine years of anemograph charts for a single station were examined. It was found that masking of important gusts did occur for some direction sectors. The data considered also raised questions related to the uncertainty of extreme gust directions.