|Abstract:||On 1-2 Feb, 2011, a mid-latitude cyclone moved through the US Midwest, covering much of the region in deep snow or sleet. This study analyzes the role that the Great Lakes played in modifying this cyclone. Two different Weather Research and Forecasting (WRF) simulations were conducted, one featuring the lakes and the other with the lakes removed. Prior to the arrival of the comma head, reverse lake effect precipitation was noted only in the with-lakes run, indicating that the lakes were effectively removed from the model. During cyclone passage, downwind modification of stability and thermal structure was noteworthy in the with-lakes run, but not in the no-lakes run. After the arrival of the comma head, small differences in the pressure field led to striated patterns in the overall liquid equivalent accumulation difference field, but these were minimal. The biggest liquid equivalent precipitation accumulation increase in the with-lakes simulation compared to the no-lakes simulation was seen in the Chicago area, downwind of Lake Michigan's long axis, but even this was barely over half a centimeter. The frontal inversion limited atmospheric moisture uptake. Large differences, however, were noted in downwind temperature and dewpoint fields, and wind fields over the lakes. Noteworthy changes were also observed in ground-level to 850 hPa lapse rates and surface layer instability.