Once the mathematical adjustment has been determined, it is applied to the long term (10 years) data published for the Met Office site. The result is the long term wind speed distribution at your site.
In order to ensure reliable results the procedure is applied to individual wind direction sectors giving a set of adjustment factors. The same procedure is followed for wind direction to give an accurate long-term wind rose.
The mathematical term for the adjustment is 'correlation' and the above procedure is known as Measure-Correlate-Predict (MCP). It is a standard procedure for the large scale wind industry but Wind Measurement International is the first to bring this approach within reach of smaller developments.