The National Weather Service says parts of the Dakotas are expected to get more than a foot of snow and that Minnesota, Nebraska and Iowa should also get significant amounts.
Some schools in the Dakotas and Minnesota have been closed for the day. Officials are advising against travel in many areas, and part of Interstate 90 in eastern South Dakota has been closed due to whiteout conditions.
South Dakota Gov. Dennis Daugaard ordered state offices closed in 13 counties.
Weather Prediction Center meteorologist Frank Pereira says the system is expected to move by midweek into the Northeast, which is cleaning up from a destructive nor'easter.