AccuWeather reports cold weather will stick around through the weekend from the Upper Midwest to the mid-Atlantic and New England.
The bitterly cold air will slosh out by the end of the week and will not dip into the Deep South. Moderate cold (lower-than-average temperatures) will remain in place into Sunday in most areas farther north.
According to Expert Senior Meteorologist Henry Margusity, "The coldest air mass in North America was sitting just north of the Great Lakes over central and northern Ontario and western and central Quebec Tuesday morning."
Temperatures reached the 40-below-zero mark in these areas and dipped below zero from northern New England to much of Michigan and areas near and north of Chicago.
"The air just north of the Great Lakes is colder than that over the North Pole," Margusity said.
The arctic outbreak is the end result of the stratospheric warming discussed a couple of weeks ago on AccuWeather.com. The cold pattern delivered by this stratospheric event generally lasts a couple of weeks to a couple of months.
Temperatures have already or will approach levels not reached in the past two to four years in a number of locations by the middle of the week from the Upper Midwest into the Northeast. In some cases, these levels are represented by daytime highs, and in others they are represented by overnight lows.
It's Not Storm-Free Cold
The southward plunge in steering-level winds high in the atmosphere, known as the jet stream, is guiding a series of storms from western Canada and across the northeastern third of the nation. These storms, known as Alberta Clippers, can bring anything from spotty flurries to a heavy snowfall.
A weak Alberta Clipper may bring spotty flurries to perhaps a coating of snow across part of southern Ohio to northern Virginia, Maryland, part of the Delmarva Peninsula, southern Pennsylvania and southern New Jersey late Wednesday night into Thursday morning.
A stronger clipper that may merge with a more southern storm has the potential to bring a swath of moderate to heavy snow from portions of the Ohio Valley to part of the mid-Atlantic coast Friday and possibly part of New England Friday night into Saturday. This storm is trending colder and farther south with its all-snow area.
Next Week and Beyond
The cold is forecast to relax next week. However, the extent of this relaxation is questionable. The latest indications are that a storm riding the crest of the warmth during the middle of the week may track farther east, rather than north. If this happens, lingering cold air near the surface could set up a large zone of a wintry mix or ice in the Midwest and Northeast.
Regardless of that major storm track next week, AccuWeather.com's Long Range Team of meteorologists expects arctic air to return in the wake of the storm during early February.
The cold air could have more staying power and as much punch as this week's event.
EDITOR'S NOTE: This story was written by Alex Sosnowski, expert senior meteorologist for AccuWeather.com.