Improvements to the 'Method of Independent Storms'

This paper presents a critical review of Cook's Method of Independent Storm s for analysing maximum hourly mean wind speeds or similar data. An improve d method is developed which eliminates the systematic errors in Cook's orig inal method, and which uses an improved set of plotting positions based on the mean values of the order statistics. A standard deviation for each plot ting portion is also derived, which enables a fitting procedure using weigh ted least squares to be adopted. This enables all the highest-order statist ics to be used, rather than a limited subset as is the case when the modifi ed Lieblein BLUE(10) method is used. The method is fully automated and a co mputer implementation is provided. Good results have been obtained for data from 5 UK meteorological sites, but the exploitation of the potential of t he new method is at present limited by UK Met Office practice of rounding h ourly mean wind data to the nearest knot. (C) 1999 Elsevier Science Ltd. Al l rights reserved.