Polar vortex to send arctic air into central, eastern US through midweek

A piece of the polar vortex will help spread arctic air across the central and eastern United States through the midweek, bringing the coldest air of the season to many.

"The polar vortex will shift southward across Canada and set up near Hudson Bay for a several-day stint during the second full week of January," said Senior Meteorologist Alex Sosnowski.

Temperatures will likely peak 10 to 20 F below-normal across the Plains, Midwest, and Great Lakes for a couple of days next week. Temperatures may not escape the single digits through the middle of the week in the northern Plains and Upper Midwest.

The polar vortex is a permanent atmospheric feature that exists near the poles. At times, it can weaken and be displaced during the winter, sending waves of arctic air farther south away from the poles.

While waves of cold like this are not uncommon during the month of January, it may come as a shocker for some due to the warm end to 2015 thanks in part to El Nino.

For those that haven't dug out the winter clothing already, this round of cold air will require several layers, especially for those heading outside for extended an extended period of time.

The frigid air will come in two waves. The first one is already in progress and will continue to dive into the Plains and push eastward through Monday. The cold will affect the NFL game in Minneapolis on Sunday.

The heart of the cold on Sunday will be located across the Dakotas to the western Great Lakes and south into Iowa. High temperatures will range from around zero to the teens in this area.

AccuWeather RealFeel® temperatures will be even lower when the wind and other factors are included. RealFeel® temperatures could drop to -30 in the Upper Midwest. Any exposed skin will be at risk for frostbite in these conditions.

High temperatures in Chicago are forecast to be in the teens Sunday and Tuesday. The last time this happened was back in early March of last year.

While the air will be moderated some as it moves south and east during the early part of the week, it will still be bone-chilling for most.

Folks in the South will need to be alert for the potential for a frost and freeze at night early next week.

"Frost will likely be seen down to the Gulf Coast Monday morning, as temperature drop near or below freezing for the first time this season in places like Houston, Mobile, and Pensacola," said AccuWeather Meteorologist Brian Thompson.

High temperatures along the I-95 corridor of the Northeast will take a steep dip on Monday, only reaching into the middle 30s. This will be a huge difference when compared with the above-average warmth from the weekend.

Temperatures around and west of the Appalachians will only top out in low to mid-20s, with a few of the colder valleys not escaping the teens.

While temperatures will plummet early in the week, the coldest air may not come until later.

"Additional waves of frigid air will rotate around the polar vortex like a giant wheel with each pushing progressively colder air farther east and south," said Sosnowski.

The second blast of cold air will arrive Monday night in the Plains and continue south and east through the middle of the week. This one will be the coldest.

"After temperatures were anywhere between 10 and 20 degrees above average during the first week of January in portions of North Dakota and northern Minnesota, high temperatures will likely be below zero on Tuesday," said Thompson.

Widespread lows in the single digits will be found as far south as Kentucky and southern Missouri Tuesday night. A stiff breeze on Wednesday will bring numbing cold air and RealFeel® temperatures in the single digits and teens across the Northeast. This includes Washington DC, Philadelphia, New York City, and Boston.

Even colder air with RealFeel® temperatures in the negative teens will be felt across the Midwest and Great Lakes at midweek.

People can help ease the impact of the cold weather in a couple of ways. Staying inside is the best bet, but if an outside adventure is in order, dress warmly and in several layers is a must.

People are also urged to make sure their vehicles are ready to go by checking tire pressure, antifreeze levels, and having a winter survival kit in the vehicle. Don't forget to bring pets inside as well.

A clipper system may bring a round of light snow to accompany the cold. Light snow will extend from the Dakotas to the Great Lakes and into New England into Wednesday. Some lake-effect snow could be triggered as well.

While the polar vortex will help bring a very cold second week of January to many, the rest of January may not be as brutal.

"Once the deep January chill this week occurs, temperatures will slowly rebound to end the month," said AccuWeather meteorologist Ed Vallee.

This will come as good news for those that despise the brutal cold weather.

"The third week will likely remain near or slightly below-average and there are some indications that the pattern moderates back above-average by the end of the month," said Vallee.