Key Points:
- A round or two of severe thunderstorms is likely Sunday into Sunday evening. Damaging wind, large hail, and isolated tornadoes are all threats.
- The timing of a cold front crossing the state Sunday is uncertain, as is how much "thunderstorm fuel" will be available. So, it is too early to pinpoint how widespread the storms will be or what areas have the highest risk.
- It's important to have a sheltering plan in place ahead of a potential severe weather outbreak. The National Weather Service has plenty of tornado and severe storm prep advice if you need it.
The busy weather pattern that looked like it would start Christmas Day a week ago is delayed but not denied as this weekend looks unsettled. We begin with chilly air trapped over South Carolina in a cold air damming setup. These setups are notorious for holding on stubbornly, and it's unlikely to see the dam break and allow warmer air to infiltrate until Saturday. By afternoon, warmer air should cover most of the state, with the wedge of cold air staying most stubborn over the Upstate, where it will hang on until Saturday night.
Cold air damming situations usually mean cloudy and often murky weather for us. Clouds will remain thick where the chilly air hangs on, with areas of fog and drizzle. The sun might peek out at times near our coast, especially as warmer air pushes in on Saturday afternoon, but I think we stay mainly gray.
Looking west, we have three storms lined up across the nation. One is generating rain and thunderstorms from Kentucky to southeastern Louisiana today. However, it's moving more northward than eastward, so the only impacts to us from it will be some light to moderate rain over the Upstate tonight and early Saturday. The second one is over the southern Plains and seems to be planning a rendezvous with the first over the Great Lakes. So that one isn't a worry for us. The next storm in line is affecting the western states today, and it's much more of a concern.

This color-enhanced infrared satellite image shows three storms lined up across the United States. Yet another storm sits just out of view over the eastern Pacific.
I couldn't resist the Seussian annotations on this chilly, damp and gray Friday that I'd rather spend playing outside.
Image Source: University of Wisconsin RealEarth
Storm 3 will make a beeline for the Southeast and will raise a severe weather ruckus over much of the region. Thunderstorms will begin over Texas and Louisiana Saturday and continue east into Mississippi and Alabama Saturday night. Beware if you're traveling that way because it could be a significant outbreak of tornadoes, damaging wind, and large hail.
The storm system pushes toward the Great Lakes Saturday night and Sunday but pulls a cold front into South Carolina on Sunday. With warm and humid air surging northward ahead of the front, we are at risk of seeing a round or two of dangerous thunderstorms that day. Forecasters at the Storm Prediction Center (SPC) have their antennae raised.

SPC's Severe Weather Outlook for Sunday has most of the Palmetto State under a level 2 of 5 slight risk area for severe thunderstorms.
We're far enough out to have some uncertainty about how high the risk will be. We know that ingredients like warmth, humidity, and wind shear will be in place, so we know all three severe thunderstorm threats (damaging wind, large hail, and isolated tornadoes) will be present.
However, we're unsure how warm it will get (that depends on how cloudy it will be ahead of the front) and how fast the front will be moving (which will determine where storms will be at the warmest and most unstable time of the day), so we can't yet pinpoint where the greatest risk will be or say for sure how widespread the severe weather will be.
So, you'll want to stay in touch and recheck the forecast on Saturday and again on Sunday morning. You'll want to have a severe weather plan in place because sometimes you don't get much lead time when a warning is issued. Determine your best shelter in advance because you might only have time to go there when you receive a warning.
Behind Sunday's cold front, a Pacific-origin air mass will move in, so temperatures won't drop much. Monday and Tuesday will remain warm as temperatures remain 10-15 degrees warmer than average across South Carolina. Both days should be dry; some clouds may linger on Monday, but Tuesday looks mainly sunny.
Another cold front should reach us by New Year's Day. Moisture with it will be limited, so there should be little to no rainfall. However, it will turn cooler behind this front, with temperatures closer to average behind this front for the first few days of 2025. We may return to below-average temperatures again as early as next weekend as the weather pattern for mid-January is shaping up to be a cold one.