On the fitting of low mean windspeed data to the Weibull distribution

Information on the frequency of occurrence of mean windspeeds between certain limits is required for a range of applications. These cover all possible windspeed values, from extreme high winds, for wind loading applications, through moderate winds for wind energy or building ventilation applications down to low windspeeds for use in risk assessments, where, although all windspeeds are relevant, these low values dominate the risk from accidental releases. The fitting of wind data to statistical distributions has previously been focused primarily on the moderate windspeed range, partly because of the applications considered, but also because of the paucity of high windspeed data, and the poor quality of most of the available low windspeed data. This paper uses good quality data, obtained from sonic or lightweight cup anemometers, to demonstrate the applicability of the Weibull distribution over the complete windspeed range.