A nearby frontal boundary coupled with several mid-level disturbances will bring the risk of strong and severe storms to parts of the Palmetto State through Wednesday.
Surface analysis Monday depicts the cold front stretched from near Atlanta, southwestward toward Birmingham and the Lower Mississippi River Valley. South of the boundary, dew points are well into the 60s and low 70s across the Lowcountry and Midlands. North of the boundary, dew points have fallen into the 50s across the Tennessee River Valley. Through midweek, this boundary will remain nearly stationary over Georgia and Alabama. The result will be a multi-day risk of storms capable of producing damaging winds, large hail, and localized flooding.
The first round of strong storms could visit the state Monday afternoon. High-resolution model guidance depicts an upper-level disturbance pivoting overhead during the peak heating of the day. This feature will enhance lift in the atmosphere, resulting in widespread thunderstorm development from the Midlands to the Lowcountry and Pee Dee. If storms are able to maintain structure without congealing into a line, the risk of large hail will be elevated. Storms are forecast to take on a more linear appearance on radar by Monday evening, however, resulting in the risk of damaging wind before storms push offshore.
Strong storms will again redevelop Tuesday, but the main risk will likely be near and southwest of the Charleston area. A thunderstorm complex is forecast to develop along the Red River Valley Monday afternoon and that system will push into Georgia and North Florida through the day Tuesday. Where exactly that complex treks will determine what area stands the highest chance of seeing strong storms. The frontal boundary is likely to wobble north and south through midweek, which adds a level of complexity to determining where severe storms will be most likely. By Wednesday, the front is forecast to bisect the Palmetto State. If this does occur, the risk of severe storms will be highest from the Midlands to the Lowcountry.
The flood risk will unfold across portions of the Midlands and Lowcountry on Tuesday, with a "marginal" risk of flooding in these areas. This designation is a 1 on a flash flood risk scale of 1-to-4. Storms will likely be slow-moving and impacting the same areas, resulting in as much as 4 inches across the Lowcountry and southern Midlands over the next seven days. If that amount falls in the course of a few hours during training thunderstorms, flash flooding will be a heightened concern in portions of the Palmetto State. Through Thursday, the risk of flash flooding will remain at least part of the weather story across the state.
By the end of the week, the boundary responsible for the multi-day risk of strong storms will push south of the area. This will not mean dry weather returns to the region, but it does mean storm chances will be closer to average for mid-June. The Climate Prediction Center suggests above average temperatures and rainfall are expected through the middle of the month.