G3 Geomagnetic Storm Triggers Mid-Latitude Auroras Visible to Wyoming and Colorado

A G3 (Strong) geomagnetic storm struck Earth late March 20 through March 21 after a coronal mass ejection launched from the Sun on March 18 impacted the magnetosphere. Solar wind speeds reached 567 km/s with the interplanetary magnetic field dropping to -28 nT. Aurora displays were visible as far south as Wyoming and Colorado. NOAA extended a G2 (Moderate) storm watch through March 23 as residual CME effects combined with fast solar wind from a coronal hole. The storm did not cause reported infrastructure disruptions, but NOAA warned of possible GPS degradation and HF radio blackouts at high latitudes — operationally relevant for Arctic military communications and PNT-dependent systems.