Impacts of Climate Change on Lake-Effect Snow in the Great Lakes Region

Lake-effect snow (LES) results from several variables meeting specifc thresholds. However, the keys thermodynamic variables related to climate change may include: the magnitude of ice coverage on the lake, the air temperature at 850 mb, and the difference between the lake surface temperature and the temperature at 850 mb. This study examined how climate change has impacted lake-effect snow (LES) across the Great Lakes region and how future climate change could influence LES in upcoming decades. The North American Regional Reanalysis (NARR) and observational datasets were utilized to quantify the frequency of each parameter meeting minimum thresholds to produce measureable LES onshore and overall trends of the LES parameters. The results demonstrated that favorable LES conditions have become more robust with time from 1979-2015 leading to more frequent and a greater magnitude of lake-driven snowfall. The same parameter and frequency trends were investigated using three regional climate models (RCMs) which have historical periods (1950-2005) and projections (2006-2100): the HIRHAM5 model with EC-EARTH parent model and the RCA4 model with both EC-EARTH and CanESM2 parent models. Historical RCM output suppresses lake warming and thus produces a less robust increase in potential LES than shown by the NARR and the observations. However, the RCM projections, when compared to reanalysis, indicate similar trends of the LES parameters, over the same time frame and lead to environments suitable for an increase in LES over the 21st century.