IR satellite imagery from late afternoon. Layered moisture is steadily progressing east from the Plains. Low level moisture in the form of dense fog and drizzle is developing over Iowa and southern Minnesota.
The first system is more of a coming attraction, with four to eight inches of snow likely in northwest Minnesota and eastern North Dakota tonight through midday on Thursday.
I expect the main feature to begin late morning on Friday and continue into the start of the New Year. The band of heaviest snow, more than six inches, should stay to the west of the Twin Cities. However, snow is likely over eastern Minnesota Friday afternoon and evening.
Here is a composite surface forecast track of the two separate low centers. The low center coming out of Kansas is the stronger system that will be over far western Wisconsin on Friday night.