No one was hurt, but a 10-yard (nine-meter) strip of the fibreglass roof was left dangling above the playing field.
The National Football League has been forced to move a game between the Minnesota Vikings and the New York Giants to Detroit on Monday night.
The storm has now moved east, dumping heavy snow on Illinois and Michigan.
Officials are optimistic about the chances of repairing the roof in time for the Vikings' next home game on 20 December.
The Vikings-Giants game had already been postponed for a day and a half because the snowstorm delayed the New York team's flight.
The Metrodome covers an area of 20 acres (eight hectares), with a 10-acre roof made of fibreglass coated in Teflon. The roof is 195 feet (60m) high and is supported by 20 electric fans.

The roof collapse forced the National Football League to reschedule a game for Monday night in Detroit, 700 miles (1120km) away