The April 2023 Severe (G4) Geomagnetic Storm

What happened

A severe (G4) geomagnetic storm struck Earth on April 23, 2023, driven by a coronal mass ejection that left the Sun two days earlier at nearly 2 million miles per hour. Aurora were reported as far south as Alabama and northern California — including sightings only about 10 miles from the Mexican border near San Diego — and NOAA issued warnings for possible power grid, GPS, and radio communication irregularities across the northern United States and Canada.