ABSTRACT
The wind and turbulence characteristics in tropical cyclones and thunderstorm downbursts, which produce the extreme winds in the lower latitudes, are equally important, but are much less well understood. As the tropical cyclone crosses the coast it weakens, and the mean wind profiles would be expected to adjust to the underlying ground roughness over the land. Choi found that the longitudinal turbulence intensity was about 50% higher in tropical-cyclone winds compared to synoptic winds. Turbulence intensities in thunderstorm downburst winds are even less well defined than for tropical cyclones. In many design codes and standards for wind loading, a peak gust wind speed is used for design purposes. Meteorological instruments used for long-term wind measurements do not have a perfect response, and the peak gust wind speed they measure is dependent on their response characteristics. Covariance and correlation are two important properties of wind turbulence in relation to wind loading.
