Columbia, South Carolina – A rare G4 (Severe) solar storm is expected to impact Earth on Jan. 20, prompting increased monitoring of South Carolina’s power grid and critical technology systems as federal space weather officials track incoming solar activity.
According to the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center, a coronal mass ejection (CME) launched from the Sun late last week is forecast to arrive late Sunday into Monday. G4-level geomagnetic storms are uncommon and can interfere with power transmission systems, satellite operations, GPS accuracy, and some radio communications, particularly across large, interconnected electrical networks.
South Carolina’s mix of coastal infrastructure, military installations, manufacturing centers, and growing population corridors increases the importance of grid reliability during severe space weather events. While the state lies south of the regions most exposed to geomagnetic disturbances, NOAA officials emphasize that widespread power outages are not expected, though utilities may take precautionary steps to protect sensitive equipment.
For most residents, the solar storm itself will not be noticeable. Experts explain that geomagnetic activity can introduce electrical currents into long transmission lines, slightly reducing the grid’s margin for error. Grid operators may increase system monitoring, adjust loads, or implement protective actions if conditions intensify.
Cell phone service and internet connectivity are expected to remain largely unaffected. However, minor GPS inaccuracies are possible, particularly affecting aviation operations, port navigation along the South Carolina coast, and precision timing systems used by transportation and emergency services.
As a secondary effect, auroras may be visible farther south than usual, with a low but possible chance of viewing from northern or inland portions of South Carolina if geomagnetic activity strengthens.
NOAA forecasters say geomagnetic activity could persist at lower levels into Tuesday.
