Why is Buffalo, NY regularly pelted with feet upon feet of snow? It's all because of the Great Lakes and how cold air gets moisture from the lakes and then dumps it on their eastern side. This image is from yesterday (or the day before - not clear). shows the effect better than I've ever seen it. In this case, Chicago, which is located approximately along the bottom of the image where the shoreline looks greenish, does not see a single flake of snow... while Grand Rapids, Michigan, 100 miles away up and to the right, is absolutely pounded with the stuff.