A cold front will sweep across the Eastern Seaboard Saturday, bringing storms capable of damaging winds and even a few tornadoes to South Carolina.
Surface analysis Thursday afternoon depicts an area of low pressure moving into the Four Corners region that is forecast to eject into the Plains by Friday. A severe weather outbreak appears likely Friday from the Upper Midwest to the Lower Mississippi River Valley, with violent tornadoes, damaging winds, and large hail possible. This system will press east through Saturday, bringing a cold front through the Palmetto State. Ahead of the approaching cold front, a combination of warm temperatures and abundant moisture will result in growing fuel for strong thunderstorms.
Models are in agreement that a broken line of storms will arrive first in the Upstate around daybreak Saturday. Storms will press east through the afternoon and evening. Strong storm potential will be maximized across the Midlands and Lowcountry, where storms will arrive during peak heating of the day. Unlike Friday's risk of severe weather, the atmosphere Saturday does not appear likely to produce widespread severe weather. However, damaging winds and isolated tornadoes are the main risks from Saturday's severe weather potential.
The isolated nature of severe storms has resulted in the Storm Prediction Center placing the Midlands, Lowcountry, and Grand Strand regions under a "marginal" risk of severe weather. This designation is a 1 on a scale of 1-to-5 for severe weather and indicates that a few strong and severe storms are possible through Saturday evening. While the risk of stronger storms will be on the lower side of the severe weather scale, residents are encouraged to remain vigilant of weather conditions throughout the day Saturday, especially if watches are issued.
Storms should press offshore by Saturday night, with northwesterly winds ushering in much cooler temperatures by Sunday. Highs Saturday to Sunday drop about 10 degrees from the Upstate to the Lowcountry as northwesterly winds drag in a cooler and drier air mass. The cooldown is likely to be brief, as temperatures by the middle of next week climb back above average.