Another polar air mass has descended into the Palmetto State, keeping us dry through the weekend. Saturday will begin in the teens and 20s, and sunshine will only warm us to the lower to middle 50s. Sunday will bring a warmup and a pretty afternoon as the high-pressure area slides off to the east. Most of the state starts below freezing, but we'll reach the lower to middle 60s in the afternoon. Enjoy that!
Things change on Monday as the first part of next week brings us our first good chance for rain in a long time. A series of storms will parade through the country, for a change being able to tap into tropical moisture. Warmer and more humid air will surge north ahead of these storm systems coming our way.
The first storm is over Texas and Mexico today; it will arrive Sunday night into Monday, with rain mainly affecting the Upstate; coastal areas should get another pleasant afternoon. The second will pass to our north on Tuesday with a trailing cold front moving into South Carolina. The front will cause rain and perhaps some embedded thunderstorms as temperatures over much of the state rise into the 70s for highs ahead of the front.
More rain and perhaps thunderstorms are likely on Wednesday as the third storm in line rides along the slow-moving cold front. The timing of the front will determine highs on Wednesday. It will reach the 70s ahead of the front but only the 50s behind it; the coastal areas are likely to be warm, the Upstate will likely be cool, and there is uncertainty for the area in between.
The rain will mostly be welcome because it's mainly been dry since Helene, except for the event about a month ago that brought flooding to parts of the Midlands and Central Savannah River Area. There will be a low-end risk for flash flooding Tuesday into Wednesday, but there is too much uncertainty to nail down the timing and areas most at risk. The same applies to a low-end risk for severe thunderstorms; the concern is there for the Coastal Plain and perhaps further northwest, but it's too early to know how widespread it will be or the exact timing.

This loop of weather maps from the Weather Prediction Center shows the progression of weather systems over the next week.
Cold air returns behind the front; days will only be in the 40s and 50s at the end of next week, and temperatures will fall below freezing at night. A warmup will follow next weekend. It's likely to remain dry for a while again after Wednesday.