UC Santa Cruz

Lake-effect snowstorms are an important element of climate and weather in the Great Lakes region of North America. Here, I investigate how lake-effect snow levels could change in the future with anthropogenic climate change as predicted by a regional climate model (RegCM3) driven by two different sets of global climate model output (from GFDL CM2.1 and CGCM3, experiments run as part of the North American Regional Climate Change Assessment Program, Phase II). I analyze a subset of the domain focused on the Great Lakes area, paying particular attention to the southeastern Lake Ontario Snowbelt and the southeastern Lake Erie Snowbelt, both of which are mainly within New York State. My results show a decrease in lake-effect snow cover in the future (2040-2070) compared to the recent past (1970-2000) for this region. Total precipitation levels are shown to not change significantly, so it is likely that lake-effect snowstorms will be replaced largely by rain in the future. Both magnitudes of values as well as trends for snow levels in specific cities varied significantly depending on which global climate model output was used to drive RegCM3, pointing to a possibly serious source of uncertainty and error in regional climate modeling studies that do not utilize multiple global climate model output.