A complex storm system is gaining strength over the Midwest as two storms will combine to dump snow from Missouri to Maine this week.
"A strong winter storm will bring the heaviest snow from the Great Lakes into New England, including cities like Chicago, Detroit, and Buffalo," said CNN meteorologist Dave Hennen.
There are more than 20 million people under winter storm alerts issued by the National Weather Service.
Monday's forecast models were predicting significant snow for Chicago. Forecasts now call for the snow band to setup farther south, leaving the city with far less snow than initially predicted.
"Chicago will likely see 3 to 6 inches in the city, with more substantial amounts south of town," Hennen says. "Detroit could pick up 8 to 10 inches, while parts of Canada could see 2 feet."
Snow will develop Tuesday and Tuesday night across parts of the Midwest and will continue into Wednesday in the Great Lakes.
The most snowfall is currently expected across southeast Michigan where 6 inches or more could fall, according to the weather service.
"Travel impacts are likely to be the most significant during the Wednesday morning and potentially afternoon commutes," the Chicago National Weather Service office said.
Snowfall rates could exceed more than 1 inch per hour in some areas Tuesday into Wednesday, leading to dangerous travel due to deteriorating road conditions and severely reduced visibility.
The storm will likely affect air travel throughout the Midwest on Tuesday and Wednesday.
Strong winds with 35 mph gusts or higher could lead to further reduced visibility.
These strong northerly winds will bring gusts up to 40 mph across Lake Michigan, increasing the possibility of lakeshore flooding. Waves of 8 to 14 feet will develop Tuesday and continue through Wednesday evening.
The weather service has issued a flood warning that covers almost 7 million people from Chicago towards South Bend, Indiana.
On Wednesday, moderate snow along with some light freezing rain is likely across northern New York and northern New England with rain near the Interstate 95 corridor, the weather service said.