Active weather is returning ahead of schedule; Wednesday will feature a risk for severe storms over the Upstate and vicinity, and then most of the state will be at risk for severe storms on Thursday.
Wednesday's storms will be triggered by an upper-level disturbance currently over Mexico and Texas. It's a weak feature, but it will have a ton of instability to work with because of the summery air mass over this part of the country. So, the Storm Prediction Center has outlined much of South Carolina for severe storm risk.
SPC's Severe Weather Outlook graphic for Wednesday with South Carolina highlighted shows the Upstate and vicinity with a level 2 of 5 severe storm risk, and most of the Midlands, Pee Dee and upper Central Savannah River Area in a level 1 risk area.
The primary concern for Wednesday will be damaging wind and hail, but there is a low-end tornado risk in the Upstate. Timing looks to be later in the afternoon into early evening for the Upstate and mainly through the evening for the rest of the area at risk.
On Thursday, a cold front will approach from the west and trigger more widespread severe storms.
SPC's Severe Weather Outlook for Thursday with South Carolina highlighted shows almost all of the state painted with a level 2 of 5 severe storm risk.
There is more uncertainty for Thursday's forecast. The uncertainty comes from what will happen to our west Wednesday night. An outbreak of severe thunderstorms will occur in the middle Mississippi Valley and vicinity starting late Wednesday, and the storms will march across Kentucky and Tennessee at night. We may see the storms cross the mountains into the Carolinas and Virginia early Thursday and push across South Carolina through the afternoon. If so, those storms could be severe. An early round of storms could limit thunderstorm potential later in the day or Thursday night as the cold front moves into the state.
However, if those storms from Wednesday's action to our west miss South Carolina to the north or diminish before they arrive. If this is what plays out, then we'd be primed for some robust storms caused by the approaching front starting in the early afternoon over the Upstate that press southeastward as the day wears on.
Either way, damaging wind, large hail, and isolated tornadoes will all be threats on Thursday. Hopefully, by later Wednesday we'll have a better idea of how Thursday will shake out, but odds seem to favor the first scenario with storms coming over the mountains into South Carolina early in the day.
Friday may also be active across the state, with the front moving slower and still over the Lowcountry. That area will see more thunderstorms and a few could be severe. Areas farther north will have a chance for a less intense afternoon thunderstorm or just a shower caused by a weak reinforcing front moving in.
This weekend will probably feature good weather before we get another unsettled stretch early next week.