Environment Canada maintains the HLY01 electronic database, which contains hourly measurements of wind speed among other meteorological parameters. The database begins in 1953 for most major airports and densely populated regions. The HLY01 database has been used for a number of climatic applications, including the estimated design wind speeds in the National Building Code of Canada. An assessment of extreme wind speeds for many Canadian locations is currently underway at the University of Western Ontario. Before the extreme value analysis could be carried out, the extracted data were manually checked for uncharacteristically high annual maximum wind speeds extracted from the station records. While quality control measures are in place and often rectify measurement problems, suspicious wind speed measurements may often be encountered during an analysis of annual maxima. These suspicious measurements may be real, or may be a result of either anemometer malfunctions or human error (more common in times when wind speeds were recorded by hand). Quite often, a malfunctioning anemometer results in a very high wind speed measurement. However, if multiple meteorological parameters (i.e., atmospheric pressure, temperature, wind direction) are considered, light can often be shed on these suspicious points, leading to an acceptance or rejection of an extreme wind speed measurement. This paper outlines this process, and is illustrated using data from selected Canadian stations. Examples are shown for cases where extreme winds were both accepted and rejected, and the characteristics of each are discussed. While the analysis of long records of data is primarily an automated process, the role of manual observation remains important.
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