Date of this Version
Winter snow cover duration has varied across the northern and central Great Plains of the United States throughout this century. Decade-to-decade variability has been common, and the timing of these fluctuations has differed considerably across the region. A general trend towards longer snow cover duration was noted from the 1920s and 1930s to the 1970s. Nine stations with continuous records of snow cover, temperature, precipitation, and snowfall dating back 61 to 97 years were studied. Snow cover fluctuations and trends are associated with changes of these other variables. Such relationships are complex and differ across the Great Plains. Correlations between winter snow cover duration and mean maximum temperature are negative in all areas, and are strongest in Nebraska, South Dakota, and southeastern Montana, where snow cover is most variable. Precipitation is correlated positively with snow cover duration in most of the region, although statistically less significant than for temperature. In the future, should the winter climate of the Great Plains deviate from what has been observed this century, it is reasonable to assume that the duration of snow cover will change significantly. Snow cover should play a role in dictating the nature of any such changes, and should also serve as a credible indicator of future winter climate change in this region.