Storm pummels Midwest with heavy snow, wind; travelers urged to stay off roads A potent winter storm pounded the Upper Midwest on Sunday with heavy snow and strong winds, making traveling treacherous and prompting airlines to cancel scores of flights. The heaviest snowfall was expected from eastern South Dakota through southern Minnesota. Forecasters said up to 16 inches was possible in the hardest-hit areas, including up to a foot in and around Minneapolis. The snow, coupled with winds gusting as high as 40 mph, could produce whiteout conditions "making travel nearly impossible," the National Weather Service said in a statement. And it wasn't just the snow that was a threat. The weather service said temperatures were expected to plummet behind the system to well below zero over western Minnesota, with wind chill readings as low as 20 to 30 below. "Travel will be very difficult and stranded motorists risk getting frostbite or hypothermia due to the frigid wind chill late this evening and tonight," the weather service said. Delta Air Lines said snow and icing conditions at Minneapolis-St. Paul International Airport prompted it to cancel about 90 flights on Sunday. The southern branch of the storm was expected to dump heavy snow in the Central to Southern Rockies, according to The Weather Channel's Tom Niziol . "As the system continues south, snow will also spread southward across the mountains of New Mexico from Taos through Sante Fe where over a foot of snow is likely for this area," he said. Snow, strong winds and cold air were also expected to hit the Great Lakes region late Sunday night into Monday.