More than 40 million people from North Carolina to Maine are under winter weather alerts Sunday morning as a storm that hit the Midwest hard on Saturday moves into the Northeast.
The storm system has brought dangerous conditions to roads, railways and airports. The Kansas Department of Transportation said one of their employees died in a crash at about 6 a.m. Saturday morning during snow removal operations in Johnson County.
The cause of the crash is under investigation. "Our KDOT personnel work very hard, at all hours, in dangerous conditions to make our roads safer for their fellow Kansas citizens," said Gov. Laura Kelly.
Two people were killed and two injured in a car accident on a snow-covered, slippery road in Kohler, Wisconsin, late Friday night, according to CNN affiliate WDJT .
The four had been traveling in a vehicle that struck a tree, according to WDJT. Police are investigating the cause of the accident, WDJT reported.
Snow and wind caused the cancellation of more than 650 flights at Chicago's O'Hare International Airport on Saturday and resulted in an average delay of 50 minutes, the airport said. At New York's John F. Kennedy International Airport, crews worked to keep runways clear Saturday night, the airport said. It encouraged travelers to confirm upcoming flights with airlines.
JetBlue announced that it has "proactively canceled approximately 770 flights through Monday."
Delta Airlines has issued travel waivers so passengers scheduled on northeastern flights affected by the weather can reschedule.
Amtrak announced modified service for more than 20 trains on Sunday because of inclement weather, after canceling service for six trains on Saturday.
'Moderate to heavy snow'
Winter storm warnings and winter weather advisories were in effect Sunday morning across a large portion of the country from the Ohio Valley and central Appalachians to the northern Mid-Atlantic and the Northeast, according to the National Weather Service.
The winter storm is expected to drop "moderate to heavy snow" Sunday morning across the upper Ohio Valley and into northwest Pennsylvania and the interior of New York and New England, the NWS said.
While snowfall is expected to taper off in the Ohio Valley and central Appalachians during the day, heavy snowfall -- as much as 1-2 inches in some places -- will continue in parts of New York and New England through Sunday night, the weather service said.
New York City can expect cold rain, and Boston will see a mix of heavy, wet snow, sleet and ice through the morning, CNN meteorologist Derek Van Dam said.
As of Sunday morning, it was snowing in upstate New York, Vermont, New Hampshire, and Maine. Heavy snow up to 2 feet is still forecast for interior portions of New England.
Cold rain is falling on New York City through much of Sunday, and winds will begin to gust up to 40 mph in the afternoon. The storm will completely move out of the Northeast and New England overnight into Monday.
A weekend of advisories
The storm has brought harsh conditions across the Midwest and through to the East coast this weekend.
Following a forecast of more than half an inch of freezing rain between northern New Jersey and southern New England, New Jersey Gov. Phil Murphy declared a state of emergency beginning at noon Saturday. He told residents to stay off the roads and prepare for possible power outages.
New York Gov. Andrew Cuomo announced a ban on tractor-trailers and buses on most highways in the state starting at 3 p.m. Saturday.
On Saturday, more than 100 million people were under some form of winter storm watch, warning or advisory from Missouri to Maine.
'Some of the coldest temperatures of the season'
The National Weather Service said Saturday the Midwest and East Coast can expect "some of the coldest temperatures of the season by Monday morning."
Temperatures are expected to drop so fast in some areas that any moisture on the ground or surrounding objects would likely freeze.
Highs on Sunday in the Kansas City, Missouri, area -- where the Chiefs will be host to the New England Patriots in the AFC Championship game -- will be in the 20s.
The extreme cold will follow the storm and move into the rest of the eastern United States on Monday.
Monday's expected high in Boston is 11 degrees, and New York City will top out at 14 degrees. The Massachusetts Emergency Management Agency is warning residents the wind chill could drop as low as 20 degrees below zero early Monday.
Cold air is expected to spill out across the country later next week as far south as Florida, leaving most of the continental United States with below-average temperatures.