Highs drop the further east you go, from above 50 in the Black Hills to only 20 in Sioux Falls.
Tonight, the new storm system arrives from the Rockies. In the warmer west, it will initially start as mainly rain before quickly turning to wintry mix; that includes freezing drizzle, sleet (the frozen ice pellets that 'clink' when they land) and eventually snow. By the morning, the system pulls together, into more of a classic line. By mid-morning, expect most of it to be snow. By afternoon, it moves east towards Aberdeen and Sioux Falls. All of KELOLAND has the potential to get something out of this. It will be gone by tomorrow night. Total accumulation will likely be highest in the northern Black Hills (possibly 2-5") and along the North Dakota border (likely less than 3").
After that, the jet stream leaves us alone for a while. The workweek looks to start a warming trend through Thursday, with highs above normal.
Two big weather stories for the weekend, then calm sailing through next workweek. Today, warmer south winds ahead of a clipper system race through KELOLAND. While that means above normal temperatures for much of South Dakota, those south winds blow fresh powder around, especially in southwestern Minnesota and northwestern Iowa. Winds will be around 25-30 mph for part of the afternoon, so something to keep in mind if you will be east of Sioux Falls.