LAUSR

Abstract It is well known that lake-effect snowfall (LES) attributed to Lake Michigan has a significant impact on transportation in the Lower Peninsula of Michigan (LPM). Better understanding of the inter-annual variability and factors contributing to LES will provide a sound basis for local and regional community safety management and improve weather forecasting. This study attempts to examine the trend in LES and its influencing factors in the LPM using station snowfall measurements and statistical analysis. LES generally increased for the period of 1933–2015 with a higher increase before 1969 and less change since 1970. The warm phase (El Nino) of the ENSO has stronger impacts on LES than the cold phase, as demonstrated by stronger negative correlations between LES and sea surface temperatures in the Nino 3.4 region (SST34) during El Nino years. Both regionally averaged air temperatures and NAO have negative correlations with LES. Further, a larger amount of LES is produced during the years with negative phases of NAO than the years with positive phases. During the years with higher maximum ice coverage on Lake Michigan, LES increases in December and January and decreases in February as the ice coverage peaks in February/March. Findings from this study can provide insight to the impact of both regional environmental variables and teleconnections on LES in the LPM.