Two CMEs impact Earth, producing G4 – Severe geomagnetic storm
Two coronal mass ejections (CMEs) produced on December 29, 2024, impacted Earth on December 31, causing G4 – Severe geomagnetic storm on January 1, 2025. A slow return to nominal levels is expected by late on January 2. Late on January 3 to early on January 4, a potential glancing blow from the January 1 CME is likely to cause another enhancement.
