A second major snowstorm is moving toward the northeastern United States on Monday after dumping more than a foot of snow in Chicago and forcing the cancelation of thousands of flights in the region. Several schools, from the Midwest to New England, were closed as storm warnings were issued for Monday by the National Weather Service.

At least 1,400 flights were cancelled out of Chicago's O'Hare Airport amid blizzard conditions, while more than 300 flights were reported cancelled out of Chicago's Midway International Airport on Monday. Authorities also forecast up to a foot of snow in parts of Michigan, Wisconsin and Iowa, local media reports said. A severe weather warning and hazardous travel advisory was reportedly issued by New York City Mayor Bill de Blasio for Monday.

“The biggest threat in this case would be ice. We would expect a lot of icing on our roads and sidewalks -- up to a quarter inch of ice in some places, and a lot of that would happen in the early morning hours, so we’d want people to be very, very cautious tomorrow,” de Blasio reportedly said Sunday.

The storm follows last week's blizzard, which pummeled parts of the East Coast, though New York City narrowly escaped the worst of the snow. Some areas north of Trenton, New Jersey, are also expected to see heavy snow, while winter weather advisories have been reportedly placed in the southern part of the state. 

"It's still intensifying and it's going to be snowing for several hours," National Weather Service meteorologist Ricky Castro said Sunday, according to Chicago Tribune. "There could be lake effect (snow) lingering, but it could keep the snow going even into the early morning hours, maybe the beginning of the morning commute will have snow falling downtown."

The weather on Sunday led to power outages in Illinois, while several other states dealt with hazardous road conditions. "It's not wise to travel, unless you have an emergency," David Beachler a National Weather Service meteorologist in the Chicago area, said according to The Associated Press.

Boston Mayor Martin Walsh said in a statement: "We are still in recovery mode from the recent blizzard, and I want to thank residents for their patience as we prepare for the upcoming winter storm," according to the Los Angeles Times, and urged residents to use public transportation when possible.