A slow-moving low pressure system will bring the potential for flash flooding and severe storms to South Carolina Thursday night into Friday.
Surface analysis Thursday afternoon shows an area of low pressure pushing across the Deep South slowly, with an associated warm front stretching east toward the Georgia coastline. This warm front is forecast to gradually lift northward through Thursday evening, bringing an increasingly moist atmosphere to the Lowcountry and Midlands. Storms began developing early Thursday afternoon along the Savannah River and have moved into areas mainly south of Columbia and Charleston as of publishing. As the warm front lifts north, dew points are expected to surge into the middle and upper 60s. This increasingly moist environment will set the stage for storms to produce torrential downpours, which could lead to localized flash flooding through early Friday across the Midlands, Lowcountry, and Pee Dee. The warm front is forecast to move across the Midlands and Upstate by Friday, bringing the flood risk closer to Columbia, Florence, and Rock Hill. Rain rates could result in the quick onslaught of flash flooding, despite generally manageable rainfall totals of around an inch. Heavier rainfall totals are going to be possible through Friday in heavy storms or in areas that are impacted by training thunderstorm activity.
Slow-moving storms will also be capable of producing severe weather across South Carolina. The Storm Prediction Center outlook for Friday depicts a "marginal" risk of strong and severe storms, or a 1 on a severe weather scale of 1-to-5. Damaging winds and large hail are the biggest threats from any isolated strong and severe storms that develop. Model guidance generally indicates the timing of strong thunderstorms to occur during the early morning hours of Friday, with locations like Columbia, Florence, and Myrtle Beach most likely to see stronger storms.
Following an unsettled end to the work week, drier conditions are expected to briefly return Saturday. Showers return to the state by Sunday as another weak surface front pushes in from the northwest.