The G3 geomagnetic storm could have minor effects on technological systems, including voltage corrections in power grids and intermittent disruptions to satellite navigation and low-frequency radio communications. NOAA has also indicated the possibility of a G4, or 'severe,' geomagnetic storm if the CMEs are more Earth-directed than current models suggest. A G4 storm could lead to widespread voltage issues, significant satellite navigation disruptions, and potential spacecraft tracking problems. Historically, auroras under G4 conditions have been visible as far south as Alabama and Northern California.