UPDATE Friday PM: The Storm Prediction Center has increased the risk level for severe storms in the far southern Low Country from a level 2 out of 5 to a level 3 out of 5. Thunderstorms are expected in this area Saturday afternoon and evening and they will be capable of producing damaging winds and tornadoes.
The Palmetto State will be transitioning from late season frost and freezes to the chance of strong thunderstorms this weekend as a low pressure system moves into the Southeast.
Through the end of the work week an upper level ridge of high pressure will continue to stay over the Southeast United States. High pressure is expected to move offshore into the Atlantic Friday afternoon helping temperatures to rise slightly for the end of the work week. Additionally, southerly winds around the high pressure system will begin to introduce an uptick in moisture to South Carolina which will set the stage for the weather pattern change expected for the weekend.
A surface low pressure over Texas on Thursday is expected to move eastward and approach the Southeast by the start of the weekend, dragging a strong cold front with it. Beginning Saturday a warm front, extending eastward from the low pressure system, will begin to lift northeastward through South Carolina. A few scattered showers and thunderstorms are possible as the warm front crosses through the region. However, following the passage of this warm front, weather models are indicating an increase in air temperatures, deep moisture, and atmospheric instability which will be increasing during the day; all of which will increase the chances of strong to severe thunderstorms forming as the cold front crosses the Palmetto State Saturday.
Showers and thunderstorms could begin as soon as Friday night in portions of the Upstate with widespread showers and scattered thunderstorms moving eastward into the Midlands Saturday and approaching the coastal regions by Saturday night. Locally heavy rainfall will be possible which could trigger localized flash flooding. Severe thunderstorms will also have the potential of producing strong winds, small hail, and isolated tornadoes.
The Storm Prediction Center, as of Thursday afternoon, has so far issued a Slight Risk (hazard level 2 out of 5) for the entire state of South Carolina excluding far northwestern portions of the Upstate which are under a Marginal Risk (hazard level 1 out of 5). This forecast could change over the next few days as the event draws closer. However, residents should be prepared for the chance of strong to severe thunderstorms beginning Friday night and lasting through Saturday.