What began as rain turned into snow in Chicago late Saturday, as a winter storm began rolling through that is expected to drop a foot of snow on the city before it moves on and hits Detroit, Cleveland, New York and Boston to make for a messy Monday morning commute, forecasters said.Meanwhile, another winter storm was still lingering Saturday over New England and dropping additional snow on the region — parts of which were already slammed with up to 3 feet earlier in the week.In total, parts of at least 15 states — spanning from Nebraska and eastward to Massachusetts— are under either winter storm watches, warnings and advisories. The newest system, which brought rain to Arizona and snow in Nebraska and Kansas, will be felt across major cities, starting in Chicago on Saturday night, according to Weather.com. The Windy City, Detroit and Cleveland could all pick up 8 to 12 inches by Sunday, said Weather.com meteorologist Tom Moore.Ohio banned tractor-trailers and other large vehicles from the Ohio Turnpike ahead of the storm, which lasts from 8 a.m. Saturday until noon Sunday.As the storm heads east, it has the potential to drop anywhere from 4 inches to a foot of snow in New York City and another foot in Boston. It could also overshadow Punxsutawney Phil's big day in western Pennsylvania as crowds turn up for the annual Groundhog Day celebration. "He's gonna wake up to snow when they pull him out of the ground. … He's not going to be a happy groundhog," Moore said.The nasty weather could also mean a delay for the New England Patriots to return from Arizona to Massachusetts after Super Bowl Sunday. And if they win the big game, there will also be the question of when to hold a victory parade.Maine, meanwhile, socked Saturday with the worst of the first snow system, coming just days after residents had dug out of some 3 feet in parts of the state. More "heavy snow," accompanied by winds reaching 40 mph, was expected in northern Maine, according to the National Weather Service, which placed the majority of the state under a winter storm warning.Southern New England only saw another inch or two of snow overnight Friday and Saturday morning. But the system moving from the Midwest to the Northeast could hit parts of New England further north. Once the snow concludes, New England and the Great Lakes region could expect temperatures in the single digits, meteorologists said.