Assessment of Potential Effects of Climate Change on Heavy Lake-Effect Snowstorms Near Lake Erie

Lake-effect snowfall in the U.S. Great Lakes region has a variety of socio-economic impacts, both positive and negative. As part of the U.S. National Climate Assessment, we are examining the potential effects of climate change on the frequency of heavy lake-effect snowfall using a statistical downscaling approach. Because lake-effect snowfall events occur at scales smaller than the resolution of current GCM models, it was necessary to relate such events to meteorological variables that exhibit spatial coherence on larger scales. Historical climate data for the period 1950-1994 were used to identify past heavy events. These events were used to construct statistical relationships between the occurrence of heavy events and meteorological variables, including screen-height temperature, lake surface temperature, wind speed and direction, 850 hPa height, and 500 hPa height. Daily data from two recent transient climate change simulations, the Hadley Center and the Canadian Climate Center simulations, are being analyzed with respect to the frequency of occurrence of the meteorological conditions conducive to lake-effect snowfall. We are comparing the frequency of occurrence between the late 20th Century and the late 21st Century portions of the simulations. These comparisons will be used to assess the likelihood of significant future changes in the frequency of such events.