The May 10-12 G5-Class Geomagnetic Storm (Invited Presentation)

The May 10-12, 2024, G5-class geomagnetic storm ranks among the most powerful space weather events of the space age. Triggered by a series of massive coronal mass ejections (CMEs) from an unusually large and complex sunspot, the storm caused significant disruption across critical sectors, including power grids, GPS systems, satellite operations, and global communications.

A series of powerful solar flares on May 7-8, and associated CMEs aimed at Earth, led the Space Weather Prediction Center (SWPC) to upgrade its geomagnetic storm watch to G4 or greater (Severe to Extreme). On May 10, the storm reached G5 (Extreme), fueled by a magnetic field 15 times stronger than usual, causing extreme geomagnetic storm conditions.

Power grids in North America and Europe faced heightened geomagnetically induced currents (GICs), prompting preemptive actions that avoided major impact to power grids, though transformer alarms and minor irregularities were reported. GPS systems were severely impacted, with aviation rerouted and agricultural operations disrupted. Satellite operators had to execute maneuvers to protect low-Earth orbit assets from increased drag and potential damage.

Thanks to SWPC's proactive communication and real-time decision support, key sectors such as the power grid operators and airlines were able to take swift action, mitigating potential catastrophic impacts. This event underscored the vulnerability of modern infrastructure to space weather, while showcasing the essential role of SWPC in safeguarding critical systems through timely forecasting and coordinated responses.

The storm serves as a stark reminder of the need for enhanced preparedness and resilience against future space weather threats.