This study uses a higher standard of data quality control for analyzing lake-effect snowfall changes
"A central assumption in this assessment is that multi-year fluctuations in snowfall will be spatially coherent and detectable at multiple stations."
This map was taken from the paper and represents the stations that passed the data quality control tests
Study Findings:
"In this study, an upward trend in snowfall was found in two of the four snowbelt areas (Lakes Superior and Michigan), both for a period of record analysis extending back to the turn of the 20th Century and for 1925–2007. The results for Lakes Erie and Ontario were mixed, depending on the period used for the trend analysis; in these two cases only a single station was available prior to 1920, heavily influencing the period of record trends."
"Specifically, air temperature has also trended upward for Superior and Michigan; therefore, it is plausible that warmer surface waters and less ice cover (Assel et al. 2003) are contributing to the upward snowfall trends by enhancing lake heat and moisture fluxes during cold air outbreaks. However, lake-effect snowfall is affected both by regional conditions, such as the state of the lake surface, and by large-scale circulation patterns that modulate the frequency and intensity of cold air outbreaks and the thermodynamic characteristics of the atmosphere. Ellis and Leathers (1996) identified trends in surface synoptic types associated with lake-effect snowfall events although that study was limited to a 32-year period ending in the 1981–82 winter."