Trends and interannual variability of wind speed distributions in Minnesota

Near-surface wind speed variability is investigated at seven stations in and surrounding Minnesota for recent climate records of 22-35 yr in length. Analyses focus on mean annual wind speeds and on the 10th, 25th, 50th, 75th, and 90th percentiles of the annual distributions of mean daily wind speeds. Most of the seven stations showed a trend toward reduced mean annual wind speeds, though one station showed increasing speeds and one station had no overall trend. In general, wind speed trends were most pronounced at the 50th, 75th, and 90th percentiles of the annual distributions, regardless of the trend in the mean. The shape and central tendency of the distributions at each station also could vary markedly from one year to the next.