Key Points:
- A Winter Storm Watch is now in effect for much of northern South Carolina, including the Upstate, Catawba Region and Chesterfield County.
A map showing the counties under a Winter Storm Watch, highlighted in blue
- Confidence continues to increase that at least a part of South Carolina will be affected by a major, long-duration winter storm this weekend.
- However, the storm's forecast track has shifted northward, lessening potential impacts for areas along and south of I-20. Timing has changed as well, with the storm starting in the afternoon or evening on Saturday and lasting into early Monday.
- The storm's details, such as precipitation type, remain uncertain. Shifting computer model output will likely lead to more forecast changes.
- Most likely scenario, not heavily favored due to uncertainty:
- Snow, if any, and sleet in the Upstate starting on Saturday, will eventually turn to freezing rain. There may be a sleet accumulation into Saturday night, and a damaging ice buildup is possible on Sunday. Travel will be hazardous through at least Monday morning. Should there be a significant sleet accumulation, it would be slow to melt behind the storm as it remains cold.
- Across the CSRA, the Midlands, and northern Pee Dee, freezing rain may dominate north of I-20, with a chance of damaging ice accumulation and slippery travel Saturday night into Sunday. Areas along and south of I-20 see freezing rain for a time, then rain as temperatures warm above freezing on Sunday.
- Areas further south and east may see freezing rain for a time Saturday night, then rain Sunday. Elevated road surfaces could become icy for a time.
- The Lowcountry and Grand Strand primarily see rain, though a period of freezing rain is possible at the onset, especially inland. Some models show it warming up enough on Sunday for thunderstorms.
- Worst-case scenarios include:
- A severe ice storm is possible where freezing rain is dominant; the best chance appears to be in the Upstate, the Catawba Region, and the northern CSRA and Midlands.
- Continued northward shifts in the storm track would shift the potential for sleet accumulations out of South Carolina, but a damaging ice storm would still occur in the Upstate. Less of the state would be at risk for a damaging ice buildup.
- A more southerly track of the storm would bring heavy snow and sleet back into South Carolina, with a damaging ice storm further south, as previously thought. This idea is looking increasingly unlikely. However, the warmer, further north computer models may not be handling this weekend's cold-air damming, and temperatures may remain below freezing near I-20 longer than the models indicate, resulting in a significant ice buildup in that area.
Good afternoon. A northward shift in the computer model guidance on the track of a winter storm for much of the nation changes the potential impacts here in South Carolina.
The forecast for now through Friday night remains unchanged:
- We remain dry through most of tonight.
- The next cold front will move in on Thursday, bringing light rain to the Upstate, possibly starting by daybreak in some areas.
- Light rain is possible over much of the state Thursday night into Friday evening as this cold front slowly sinks southward.
- Arctic air will filter into South Carolina behind this front starting Friday evening.
Our next storm, currently approaching California, will reach us on Saturday. It has become unlikely that any significant snow will fall in the state (a little at the onset maybe), but sleet and freezing rain are likely to affect much of the state. The computer models continue to show a range of possibilities, but the trend has been our friend, showing less of the state experiencing significant impacts.
It would be best to start your preparations soon if you're in an area that still may be hit by a damaging ice storm and slippery travel. How do you deal with it? SCEMD's SC Winter Weather Guide is a good starting point, and you can get more tips on winter storm preparedness at ready.gov. Pay close attention to the generator safety and kerosene and propane heater safety tips; carbon monoxide is quite the villain.
The picture should get increasingly clearer over the next couple of days as we get closer to the event. Another update is coming on Thursday!
