Arctic air is spreading across the nation behind the departing winter storm, which produced heavy snowfall and ice for millions including parts of South Carolina.
Forecast models indicate temperatures will drop 20 to 30 degrees below normal, with some areas of the Upstate potentially falling into the single digits for overnight lows.
The cold snap is expected to last several days, making the airmass more extensive than previous cold weather outbreaks so far this season.
A factor contributing to the cold air is the extensive ice and snowpack, stretching from the Desert Southwest through the Plains and into New England.
Extensive snowfall can act as a conveyor belt for cold air, allowing it to make it all the way through the South and to the Guld Coast, without significant moderation.
Because of widespread temperatures in the teens and 20s, with feels like readings even colder, a Cold Weather Advisory will likely be in effect during the overnight hours on the coldest nights.
The “Cold Weather Advisory” designation debuted in 2024 as part of NOAA’s hazard simplification initiative and replaced what was previously known as a "Wind Chill Advisory."
The wind chill plays a significant role in how the cold air actually feels on the body.
For example, if the air temperature is 30 degrees and the wind is blowing at 10 mph, it will feel closer to 21 degrees. If the air temperature drops to 20 degrees with winds still at 10 mph, it can feel more like 8 degrees.
At temperatures falling to expected levels, frostbite and hypothermia become real concerns, as a body can rapidly lose heat.
The National Weather Service warns that hypothermia can begin to develop with prolonged exposure to cold air, even at temperatures well above freezing.
Hypothermia occurs when the body’s temperature drops below 95 degrees, which can become life-threatening in just minutes.
Residents who lost electricity during the winter storm are encouraged to take advantage of warming shelters, until power can be restored.
Local authorities also recommend homeowners allow a faucet to drip overnight in structures with older or unprotected plumbing to reduce the risk of pipes cracking or bursting.
Travelers should also prepare for the blast of cold air by checking battery level, tire pressure and keeping an emergency kit in their car in case they become stranded.
High pressure will remain in control for the next several days, leading to sunny weather, but as the weekend approaches, some forecast models hint at a disturbance around the Southeast, which could produce at least a few snow flurries.
There is still plenty of time to monitor the potential system, and adjustments will be made to the forecast throughout the week.
Long-range outlooks suggest the colder-than-normal pattern could persist through the end of January and well into February before a warmer pattern becomes established.