nr ganim thousands of fligths canceled_00012611.jpg
nr ganim thousands of fligths canceled_00012611.jpg
Now playing
01:56
More than 2,000 flights canceled
daylight saving jennifer gray explainer orig_00001506.jpg
daylight saving jennifer gray explainer orig_00001506.jpg
Now playing
01:32
Daylight Saving Time: Why we have it
Now playing
01:54
Why snow and blackouts in Texas are a preview for all of us
Now playing
00:52
Truck slides down slick hill after winter storm
Storm chasing photographers take photos underneath a rotating supercell storm system in Maxwell, Nebraska on September 3, 2016. Although multiple tornado warnings were issued throughout the area, no funnel cloud touched down. / AFP / Josh Edelson / XGTY
RESTRICTED TO EDITORIAL USE  / MANDATORY CREDIT:  "AFP PHOTO / Josh EDELSON" / NO MARKETING / NO ADVERTISING CAMPAIGNS /  DISTRIBUTED AS A SERVICE TO CLIENTS  ==        (Photo credit should read JOSH EDELSON/AFP/Getty Images)
JOSH EDELSON/AFP/AFP/Getty Images
Storm chasing photographers take photos underneath a rotating supercell storm system in Maxwell, Nebraska on September 3, 2016. Although multiple tornado warnings were issued throughout the area, no funnel cloud touched down. / AFP / Josh Edelson / XGTY RESTRICTED TO EDITORIAL USE / MANDATORY CREDIT: "AFP PHOTO / Josh EDELSON" / NO MARKETING / NO ADVERTISING CAMPAIGNS / DISTRIBUTED AS A SERVICE TO CLIENTS == (Photo credit should read JOSH EDELSON/AFP/Getty Images)
Now playing
00:59
The difference between a tornado watch and a warning
DODGE CITY, KS - MAY 24: A tornado is seen south of Dodge City, Kansas moving north on May 24, 2016 in Dodge City, Kansas. About 30 tornadoes were reported on Tuesday in five different states from Michigan to Texas. Damage to homes and property was also reported in Ford County, Kansas. (Photo by Brian Davidson/Getty Images)
Brian Davidson/Getty Images
DODGE CITY, KS - MAY 24: A tornado is seen south of Dodge City, Kansas moving north on May 24, 2016 in Dodge City, Kansas. About 30 tornadoes were reported on Tuesday in five different states from Michigan to Texas. Damage to homes and property was also reported in Ford County, Kansas. (Photo by Brian Davidson/Getty Images)
Now playing
01:41
How to prepare for severe weather
Courtesy Amy Lloyd
Now playing
01:06
Why flash floods are so dangerous
Franck Verdière/Twitter
Now playing
01:10
What 'rapid intensification' means for storms
Now playing
01:29
Steer like this to stay out of accidents in the snow
nor'easter explainer orig nws_00002211.jpg
nor'easter explainer orig nws_00002211.jpg
Now playing
01:03
What is a nor'easter?
east coast storm waves noreaster orig mg_00001813.png
Brandon Clement / Live Storms Media
east coast storm waves noreaster orig mg_00001813.png
Now playing
01:07
Massive waves crash over top of coastal homes
Larry Pierson, from the Isle of Palms, S.C., purchases bottled water from the Harris Teeter grocery store on the Isle of Palms in preparation for Hurricane Florence at the Isle of Palms S.C., Monday, Sept. 10, 2018. (AP Photo/Mic Smith)
Mic Smith/AP
Larry Pierson, from the Isle of Palms, S.C., purchases bottled water from the Harris Teeter grocery store on the Isle of Palms in preparation for Hurricane Florence at the Isle of Palms S.C., Monday, Sept. 10, 2018. (AP Photo/Mic Smith)
Now playing
00:57
How to prepare for a hurricane
IN SPACE - In this handout photo provided by NASA, Hurricane Patricia is seen from the International Space Station. The hurricane made landfall on the Pacfic coast of Mexico on October 23. (Photo by Scott Kelly/NASA via Getty Images)
NASA
IN SPACE - In this handout photo provided by NASA, Hurricane Patricia is seen from the International Space Station. The hurricane made landfall on the Pacfic coast of Mexico on October 23. (Photo by Scott Kelly/NASA via Getty Images)
Now playing
01:07
Why hurricanes are so hard to predict
Now playing
01:26
Hurricanes: What you don't know
LAS VEGAS, NV - JULY 07:  Lightning strikes during a thunderstorm on July 7, 2015 in Las Vegas, Nevada. The monsoon storm dropped heavy rain and hail in parts of the valley causing street flooding and power outages.  (Photo by Ethan Miller/Getty Images)
Ethan Miller/Getty Images North America/Getty Images
LAS VEGAS, NV - JULY 07: Lightning strikes during a thunderstorm on July 7, 2015 in Las Vegas, Nevada. The monsoon storm dropped heavy rain and hail in parts of the valley causing street flooding and power outages. (Photo by Ethan Miller/Getty Images)
Now playing
01:36
How to protect yourself from lightning
Now playing
01:21
What is a polar vortex?

Story highlights

A winter storm is bringing snow, sleet and freezing rain to Plains states

A foot of snow is forecast for some states and local accumulation could go higher

The storm is expected to impact Northeastern Seaboard states hit by blizzard last week

(CNN) —  

A winter storm ramping up in the Great Plains put the metropolitan Chicago area’s more than 9 million people under a blizzard warning Sunday, and another 65 million people are under a winter storm warning across 18 states. The storm has the Northeast in its sights next.

Chicago could get as much as 15 inches of snow from the storm system, CNN meteorologist Michael Guy said.

“The streets will stay plowed and passable so people will be safe and secure,” Chicago Mayor Rahm Emanuel promised at a news conference Sunday. More than 350 pieces of equipment, including plows and salt spreaders, fanned out across the city, officials said.

Up to a foot of snow was forecast in parts of Iowa, Illinois, Michigan and Wisconsin. Multiple winter storm warnings are in place from eastern Nebraska and South Dakota to the Plains.

The storm will move east and affect major metropolitan areas such as New York City and Boston on Monday, Guy said. “New York City could see a wintry mix of precipitation just in time for the morning commute with a possibility of sleet and ice,” and Boston will “get another round of wintery weather with new snow accumulations from 10 to 12 inches,” he said.

More than 2,000 U.S. flights were canceled Sunday, many of them in and out of Chicago, according to Flightaware.com, an online flight tracking service.

“Rain will be the problem across the southern portions of this storm system, with a possibility of scattered storms from east Texas to Mississippi Sunday as the storm moves east.,” Guy said.

CNN’s Kimberly Hutcherson, Joe Sutton, and meteorologist Derek Van Dam contributed to this report