The clock is ticking on extensive mild, Pacific air that has infiltrated much of the United States in the past week. AccuWeather meteorologists advise that drastically colder air from the Arctic will invade the Central, Southern and Eastern states and could set up a stormy pattern with areas of substantial snow and ice for much of the first half of January.
The severity of the cold air could be dangerous, damaging and disruptive. At the very least, the upcoming pattern could be costly for those struggling to pay energy bills and travelers heading home from the holidays or beginning business trips for the first couple of weeks of 2025.
The jet stream pattern, which has been generally west to east this weekend, will soon develop a large southward buckle. As this occurs, the doors to the Arctic will open.
The big dip in the jet stream will evolve in stages next week and not in one sudden, massive shift.
The first exploits of colder air will begin during the middle and latter part of next week in the wake of a storm that transitions the end of 2024 and the beginning of 2025.
“Some of the first sub-zero F temperatures will occur over parts of the northern Plains late this week, then will back off,” AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
But then, as the jet stream dip continues to evolve, the Arctic Express will kick into high gear during the first full week of January.
“The first Arctic high pressure area will sink southward across the Plains and impacts Texas early next week,” Pastelok said, “This airmass will continue to follow the storm along the Gulf Coast, Tennessee Valley and Southeast between Jan. 8-9.”
The end result will direct a significant amount of Arctic air directly southward over the North Central states then into parts of the South Central and Southeast states.
For example, around Chicago, mild conditions with highs in the 40s F are in store into Tuesday. However, in the wake of progressively strong pushes of Arctic air, highs from Friday through next weekend will be no better than the 20s then no better than the 10s from Jan. 7-10.
At the pit of the Arctic outbreak air before the middle of the month, temperatures may trend far below the historical average for what is typically some of the coldest days of the winter.
As the cold air deepens and tightens its grip before the middle of January, subzero temperatures will be felt over a portion of the North Central states. As more information becomes available, temperature forecasts may trend downward.
Should the cold wave evolve to its full potential, temperature departures could plunge to 30 to 40 degrees below the historical average from the Midwest to the interior Southeast at peak during the first to second full week of January.
Cold air of this magnitude over hundreds of thousands of square miles could result in power grid issues with the potential for rolling blackouts.
As much colder air blasts across the Great Lakes and into the Northeast in waves, it will unleash shifting bands of heavy lake-effect snow that can hamper travel, increase the risk of multiple vehicle pile-ups and even close some major highways at times. Multiple feet of snow may bury some communities where the bands of heaviest lake-effect snow persist.
This pattern is likely to be strewn with various storms of different magnitude and tracks. Depending on exactly where these storms travel, a band of heavy snow and wintry mix is likely to occur just to the north and west of the center of low pressure for each system.
While it is too far out to pinpoint the exact track of storms, the upcoming pattern is conducive to supporting storms that bring snow or a wintry mix instead of plain rain to many areas.
Not only may some storms bring a general snowfall or two to parts of the Midwest, but there is also some risk that accumulating snow may reach the mid-Atlantic and New England coasts and perhaps parts of the South Central and Southeast states.
“Where the storms produce a significant snowfall, that snow cover will assist with the southward spread of more Arctic air,” Pastelok said.
Major metro areas such as Chicago, Boston, New York City, Philadelphia, Washington, D.C., Charlotte, Atlanta and others could be on the receiving end of accumulating snow during the pattern. It is not entirely out of the question that at least one of the storms late next week will attempt to bring a period of snow and/or ice to the zone from Houston to New Orleans.
This type of weather pattern, occurring during some of the historically coldest days of the winter, has a significant chance of leading to major travel disruptions and, most certainly, a surge in energy demand in much of the central and eastern U.S.
“Given the setup as we see it now, the anchor for the cold air may be centered over the Midwest rather than the Northeast,” AccuWeather Senior Meteorologist Brett Anderson said. “The pattern favors storms weakening as they push into the Ohio Valley, but then re-form along the mid-Atlantic coast. An atmospheric roadblock over eastern Canada may prevent the storms from traveling too far to the north, and the main snow threats may shift farther south than what has occurred so far this winter. Accumulating snow could end up over part of the mid-Atlantic region and interior Southeast for part of the first half of January.”
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The penetrating waves of cold air into the South Central and Southeast states could lead to problems with frozen pipes and water damage in poorly insulated or exposed homes and buildings during the pattern.
“We will be closely monitoring how far south the cold air is able to press in crop-vulnerable areas such as Florida, southern Louisiana and Texas,” AccuWeather Meteorologist Alex DaSilva said. “It is possible that freezing temperatures may reach these far southern locations in the pattern during the first half of January.”
It is possible that portions of the Southern states experience many consecutive hours or days where temperatures remain below freezing. Some pump systems may struggle to keep up. Similar Arctic outbreaks in the past have tested the electric grid.
“The key here is that the Arctic outbreak will involve many days and not just be a quick one-to-three-day event,” Pastelok said, “A trainload of Arctic high pressure areas will move southward into the U.S. from the northern Plains to the Southeast states with the pattern.”
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