Sprawling high pressure aloft over the central part of the country will keep warmer-than-normal temperatures in the forecast through Christmas and heading into the weekend. There are changes coming, though, in the form of an Arctic blast that will bring 2025 to a chilly end.

The main weather story for the week ahead — including Christmas Day — will be much warmer-than-normal temperatures as high pressure aloft will remain the dominant weather feature across a good bit of the continental US.

It’ll be a quiet and seasonable weekend of weather in the Lowcountry as we embark on the last shopping weekend before Christmas. Temperatures Saturday will start on the cool side, with calm winds and clear skies allowing temperatures to fall to the mid-30s by morning. Mostly sunny skies will help temperatures warm to the low 60s in the afternoon, about right where we should be for December 20.

The airmass moderates a bit on Sunday ahead of another front. We’ll start the day in the low 40s, warming to the mid-60s in the afternoon with mostly sunny skies once again expected. The frontal passage late Sunday will be dry, but will bring a decent shot of cool air to start the abbreviated work week on Monday. We’ll warm back up for Christmas, though, and may even crack 70° on Christmas Day, as we look to close 2025 on a warmer-than-normal note with sprawling high pressure developing aloft across much of the continental US.

A front will sweep away the dreary and damp Thursday, yielding a much nicer Friday with much more sunshine. We’ll start the day in the mid-50s with some cloud cover still hanging around, but that should depart by midday. Temperatures will warm to the mid-to-upper 60s with breezy westerly winds, which will be gusty early in the day, peaking in the 20-25 MPH range. Winds will gradually slacken some as the day goes on, though.

We’ll continue to put Monday’s cold snap in the rear view on Wednesday as temperatures continue to trend warmer with high pressure moving eastward. Temperatures will fall to the mid-30s overnight, but increasing cloud cover should keep a lid on further radiational cooling and keep us above freezing. From there, we’ll warm into the low-to-mid-60s as the cloud deck continues to thicken courtesy of a coastal trough taking shape offshore.

While it won’t be as windy as it was on Monday morning, we still have quite a frigid start queued up for Tuesday as lows drop back to the low 20s in the morning, with some upper teens possible closer to and west of I-95. However, with high pressure beginning to slip to the east, we’ll start to see temperatures begin to moderate in the afternoon as mostly sunny skies prevail. While the forecast high of 54° remains well below normal for this point in December, it will feel tropical in comparison to Monday’s high of 39° at the airport (which ties the record cold high temperature first set in 1942).

The well-advertised cold snap is underway as Arctic air pushes into the area, with air temperatures expected to fall to around 20° in the morning. While the most gusty winds should subside overnight, a 10-15 MPH breeze out of the north will continue to drive wind chills down well into the teens, with the potential for some brief sub-10° readings as well. A Cold Weather Advisory will run until 10am Monday to cover the most bitter cold, but it will still be a very chilly day with highs struggling to break 40° under mostly sunny skies. Winds will be slackening a little throughout the day, but still should be elevated enough to make it feel more like the mid-30s. Layer up and ensure pets, pipes, plants, and people are protected.

My advice to folks for this weekend: get out and about Saturday as much as you can, soaking in what passes for warmth during this rather chilly December, because another shot of very cold air is enroute to start the new week.

Saturday starts in the low-to-mid-40s, warmest near the coast. Southwesterly flow around high pressure to our east will help drive temperatures into the mid-to-upper 60s in the afternoon with just a few clouds at times. It’s going to be a pretty nice day, so get out and enjoy it!

The front arrives Sunday. A few showers are possible out ahead of the front, but many of us may stay rain-free. The front itself passes through around midday or so, and we should see temperatures begin to fall off in the afternoon. We’ll peak in the upper 50s to around 60° relatively early in the day as a result. Once the sun goes down, temperatures will plummet below freezing by midnight and will continue to fall heading into Monday morning.

A brief warmup is in the cards for Friday and again on Saturday before a front moves by with some showers Sunday. This front will usher in a bitterly cold Arctic airmass that’ll plunge temperatures into the low 20s by Monday morning.

Another dry front will come through overnight with a reinforcing shot of cooler air for our neck of the woods, but at least we won’t be starting the day with freezing fog like we did this morning. Freezing fog occurs when fog develops at temperatures below freezing, producing a glaze of ice on surfaces it comes into contact with (generally elevated surfaces). This morning, temperatures fell to the dewpoint of 28°, which aided in its formation and caused quite a few problems on bridges and overpasses, with numerous traffic accidents and closure of both the Don Holt and North Bridges. Freezing fog is incredibly, incredibly rare for this part of the world — in fact, this morning’s Freezing Fog Advisory was the first ever issued for the Charleston metro area, and only the second issued by NWS Charleston, SC (the first one was issued in 2022).

Thankfully, we will not deal with this Thursday morning as temperatures are expected to stay above freezing, generally running in the upper 30s to around 40°. The aforementioned dry front comes through early in the day, and this helps usher in another shot of cooler air that’ll keep things breezy and chilly Thursday afternoon, with highs only reaching the low 50s despite partly cloudy to mostly sunny skies. Morning wind chills may bottom out in the low 30s, so layer appropriately.