CNN
—

Bitingly cold temperatures – below freezing in some areas – will sweep across much of the United States on Sunday, while record-breaking lake-effect snow will make post-holiday travel treacherous and nearly “impossible” in parts of the Great Lakes region.

In parts of New York, Pennsylvania and Ohio, people faced low temperatures and several feet of snow over the weekend.

Near Lake Erie in Conneaut, Ohio, where additional snow amounts of up to 5 inches could accumulate on Sunday, the roof of a home appeared to be covered in snow on Saturday, according to a video shared with CNN by resident Ashley Drew has. The house’s blue front door was only partially visible behind a wall of snow as snow continued to fall.

Nearly 70% of the continental U.S. will feel the chill of temperatures below 32 degrees over the next few days. Some areas, including New York City, Chicago, Atlanta, Minneapolis and Cincinnati, will experience below average temperatures throughout the week.

Four million people are currently under snow warnings due to lake effects, which expire Sunday night through Monday.

In Amherst, New York, in Erie County, subfreezing temperatures prompted authorities Saturday to issue a Code Blue Alert, urging anyone who needs shelter during the extreme cold to call for help.

Erie County is among 11 counties declared under a state of emergency that New York Gov. Kathy Hochul declared Friday in response to ongoing lake-effect snowfall that began late Thursday.

The declaration impacts western and central New York and includes the Buffalo area and many areas near Lakes Erie and Ontario.

“My administration is working around the clock to respond to the snowstorm in Western New York and the North Country,” Hochul said Saturday. “Our state authorities and over 100 National Guard members are on site to support storm operations.”

Pennsylvania Gov. Josh Shapiro also called out his state’s National Guard on Saturday to help any stranded motorists and ensure emergency responders can reach anyone trapped, he announced on X.

The outbreak of Arctic cold pushing south from Canada will cause temperatures to fall as much as 15 to 25 degrees below average across much of the eastern half of the U.S. by the middle of next week, forecasters say.

“High temperatures are expected to be 10 to 20 degrees below average from the Northern Plains to the Ohio Valley on Sunday and Monday, with 10 to 20 degrees below average temperatures spreading further southeast along much of the East Coast through Monday,” says the National Weather Service Weather Prediction Center.

Wind-driven cold air flowing over record-warm waters in the Great Lakes is responsible for lake-effect snow, which meteorologists say has already dumped up to dozens of inches of snow in some places.

Another 3 feet of snow could fall in parts of Pennsylvania, northern Ohio and western New York by Monday. An additional 3 to 5 feet of snow could fall in Watertown, New York, according to CNN meteorologists.

“The highest snow amounts are expected downwind of Lakes Erie and Ontario, affecting areas of northeastern Ohio, far northwestern Pennsylvania, western New York State and portions of northwestern New York State,” according to the Weather Prediction Center.

North East, Pennsylvania, a county in Erie County, recorded just over 42 inches of snow between Thursday night and Saturday afternoon, while Erie, Pennsylvania saw 31 inches. According to the weather service, 45 inches of snow fell in Barnes Corners, New York, on Saturday afternoon.

Nearly two million people remain under a snow warning due to lake effects until early Monday.

Video showed several homeowners in Erie, Pennsylvania, shoveling large piles of snow by hand and using snow blowers to clear mounds from their driveways and sidewalks as snow continued to fall Saturday, CNN affiliate WICU reported.

Another video from storm chasers showed mounds of cars buried under snow in Erie County, Pennsylvania.

Kathy Davis, a resident of Tug Hill in upstate New York, described Saturday’s heavy snowfall as “good, old-fashioned winter” in a video clip she shared with CNN affiliate WWNY.

“That’s what I remember as a kid,” Davis said, according to WWNY. “It just keeps coming and coming.”

Matt Eisert, 58, of Columbus, Ohio, said he was visiting his father in Erie, Pennsylvania, during Thanksgiving when his parents’ home was surrounded by heavy snow.

“We grew up here, so we were always used to snow acting like a lake when the warm, unfrozen lake evaporates because cold winds blow over it,” Eisert said.

The broker said he still plans to return to Columbus sometime Sunday and that the trip is expected to take longer than three hours.

“I have blankets in the car, water and some protein bars. I always stock up on supplies and keep a little road survival kit in my car,” Eisert said.

Multiple highway traffic cameras showed snow on highways in Ohio, Pennsylvania and New York on Saturday.

The Ohio Department of Transportation in Akron said 25 crew members were working around the clock in Ashtabula County as snow caused by lake effects continued to fall in the county, where commissioners declared a state of emergency on Saturday, the said County Board of Directors via Facebook.

Post-holiday travel will continue to be “very difficult to impossible” for some drivers, and forecasters are advising people to stay off the roads as snowy conditions make driving “treacherous and potentially dangerous,” according to the National Weather Service office in Buffalo, New York.

“Delay all travel. If you must travel, drive with extreme caution,” the weather service warned Saturday. Buffalo’s lake effect snow warning remains in effect through Monday night.

Meanwhile, in a post on X-Saturday, the Buffalo Bills showed snow covering the field at their open-air Highmark Stadium in Orchard Park, New York. The team is scheduled to play the San Francisco 49ers on Sunday night.

The Bills began asking fans for help Friday to clear snow from the field before the game. Erie County officials in New York said Friday they do not expect snow conditions to impact the game.

According to the New York State Weather Risk Communication Center, lake effect snowfall is expected to occur over Orchard Park until 4 p.m. ET Sunday.

CNN’s Gene Norman, Allison Chinchar, Artemis Moshtaghian, Taylor Galgano and Sam Joseph contributed to this report.