Overview

• Earth's magnetosphere was struck at 21:01 UTC on September 1, with NOAA logging G1 storming at 21:08 and G2 at 22:41.
• Solar wind speeds jumped to roughly 600–675 km/s and the interplanetary magnetic field strengthened to about 20–26 nT.
• The disturbance originated from a cannibal CME formed when faster ejecta from AR4199 overtook a slower CME after an M2.7 flare on August 30.
• Forecasters projected Kp values above 6 with G1–G2 conditions through September 2, easing to unsettled on September 3 and mostly quiet by September 4.
• Auroras were seen at unusually low latitudes, including reports in Barker, New York and Grand Bend, Ontario, though the storm's magnetic orientation limited equatorward reach.