Ethermac|Chill spilling into the US this week with below-average temperatures for most

It's beginning to look a lot like − winter. And that could Ethermacbe bad news for Americans heading home from the Thanksgiving holiday.

Below-average temperatures are likely to saturate most of the country to start the workweek, the National Weather Service said Sunday.

One of the biggest trouble spots is expected in the Great Lakes region, where some of the chilliest air of the season will trigger lake-effect snow, forecasters say, and travel could be treacherous from portions of the Midwest to the Northeast.

About 1-3 inches of snowfall rates per hour, power outages and whiteout conditions were possible in some of those areas from Sunday night into late Tuesday, according to Accuweather.

"Travel headaches will abound along I-90 from just south of Buffalo, New York, all the way to Cleveland during the first half of the week due to heavy snow coming off the lake," AccuWeather meteorologist Jake Sojda said.

What is the Sunday-Monday travel forecast?

Thanksgiving travelers heading home from the Plains to the West Coast can expect few issues Sunday, the National Weather Service said. But in addition to lake-effect snow cranking up in the Upper Great Lakes, the ride could be bumpy elsewhere. Moderate to heavy rainfall was possible along the Gulf Coast and the northern mid-Atlantic to New England coasts, the weather service said.

Wintry weather could make travel dicey in cities such as Minneapolis, St. Paul, Chicago, Milwaukee and Detroit even though big snow accumulations aren't likely, Accuweather warned.

Fatal crashes reported:Thanksgiving holiday weekend travel safety news

The Transportation Security Administration projected that Sunday could set travel records: An estimated 2.9 million people could board flights, surpassing a previous record of more than 2.8 million passengers on Dec. 1, 2019.

“We expect this holiday season to be our busiest ever. In 2023, we have already seen seven of the top 10 busiest travel days in TSA’s history,” TSA Administrator David Pekoske said.

 AAA projected the Thanksgiving holiday would see more than 49 million drivers on the roads, an increase in 1.7% from last year.

What is a bomb cyclone?A winter hurricane, explained.

How intense will the lake-effect snow be?

The lake-effect snow that will spread across the Great Lakes region could spur whiteout conditions "in a matter of seconds" as heavy snow bands and gusty winds grip the area, Accuweather warned. Thundersnow − a winter thunderstorm that produces snow instead of rain − is also possible, forecasters said.

Road closures were possible along Interstate 81 from Syracuse to Watertown, New York, Interstate 90 in western New York and northeast Ohio and Interstate 94 and 196 in Michigan, Accuweather said. In some of those areas, "snowfall totals are likely to exceed 1 foot," Sojda said.

Contributing: Cybele Mayes-Osterman