A low pressure system tracked from the southern Plains during the evening of the 27th, to far southern Lake Michigan by the afternoon on the 28th, and into Lower Michigan by evening. Snow overspread southern Wisconsin by early morning and continued through much of the afternoon. Snow became very heavy at times with visibilites near 1/8 of a mile for a time during the early afternoon. The snow diminished from southwest to northeast across the area during the early evening. Total snow accumulations across southern Wisconsin ranged from 3 to 8 inches, with the heaviest amounts over Waukesha county. Despite the heavy snowfall, many roads responded very well to salt because temperatures were hovering around the freezing mark.
Below is a statewide snowfall map of the December 28, 2007 snowstorm: