Ashley R Williams - USA TODAY
Bitterly cold temperatures and a significant winter snowstorm could threaten holiday travel plans for millions across the U.S. from the Plains to the Eastern Seaboard.
This week’s blast of frigid air comes as an earlier system winds down after burying parts of the Northeast under 2 feet of snow.
The U.S. may experience “the coldest air of the season” as a strong arctic front marches across the eastern two-thirds of the country days before Christmas, according to the National Weather Service’s Weather Prediction Center.
"I have to imagine we're going to be pretty darn close to low-temperature records in a lot of the Northern Plains," AccuWeather senior meteorologist Adam Douty told USA TODAY.
Here’s what to know about the frigid week ahead.
What regions will get hit with snow, chilly temps?
The storm’s greatest impacts will affect the Great Plains region over to the east, according to Douty.
Pretty much everyone, at least east of the Rockies, is going to feel the effects of it in one form or another – whether it's rain, snow, wind or colder temperatures,” Douty said.
The storm is expected to result in mostly rain and wind across the Ohio Valley and along the East Coast in cities such as Washington, D.C., New York City, Philadelphia and Boston on Thursday and Friday.
“By the time the cold air gets to the East Coast, it looks like a lot of the moisture is going to be gone, and when the rain ends, the cold air comes in,” Douty said, adding that the eastern cities shouldn’t anticipate a snow threat.
What's the timing of the cold, snowy conditions?
Forecasters expect snow to fall across the Northern Rockies on Tuesday into Wednesday.
The most significant impacts are expected later Wednesday night as cold air dives south across the Plains. South Dakota, Nebraska, Kansas and Colorado are likely to receive “a little batch snow” late Wednesday followed by frigid temperatures, according to Douty.
Denver’s high temperature Wednesday is forecasted to be 37 F – and by Thursday, the city will be shivering as the high dips to minus 5 F, he said. The extreme temperature dip could be the most notable aspect of the wintry conditions over the week’s second half, Douty said.
“Especially once you get outside the Midwest where they’re going to see heavy snow, the temperature drop across all of the eastern U.S. is going to be 20 to 30 degrees from one day the next after this storm goes through,” he said.
An exceptionally cold air mass over western Canada that is pressing south toward warmer air is causing the anticipated temperature drops the first half of the week over the majority of
the lower 48 states, according to weather experts.
AccuWeather forecasters predicted the Central Plains, Nebraska and Kansas would experience the heaviest snow, while Chicago could see up to 6 inches of snow from Thursday to Friday.
As the storm moves east, strong widespread winds 40 to 50 mph could pick up across the Central Plains and Midwest into the Great Lakes and Ohio Valley, leading to blizzard conditions for areas expecting heavier snow later in the week, Douty said.
Should pre-Christmas travelers expect delays?
Travelers flying or driving home for the holidays can expect a “big mess” across much of the eastern U.S. in the days leading up to Christmas, according to Douty.
“There could be massive delays flying in and out of the East Coast and those could trickle even to the West Coast, so places that aren't (getting the storm directly) could see travel impacts rippling across the country,” Douty said.
Blizzard conditions from Thursday into Friday could cause travel headaches for drivers in the Midwest amid potential road closures, particularly across parts of Iowa, northern Missouri and parts of Wisconsin and Illinois, he said.