A powerful winter storm barreling across the northern tier of the country has begun unloading heavy snow across multiple states, prompting delays on roads and at airports as officials warn of dangerous travel conditions.
Tens of millions of people were under blizzard and winter storm warnings on Dec. 29 from Minnesota and Iowa to Michigan, New York and Maine, according to the National Weather Service.
More than a foot of snow was expected across the upper Great Lakes region, federal forecasters said, with double that amount possible along the south shore of Lake Superior.
More: Messy weather threatens post-holiday travel across US. See forecast.
Weather officials told people to avoid traveling, warning those who must drive to bring a winter survival kit with them in case they get stranded. Visibility in some areas could be near zero, meteorologists said.
