Overview
- NOAA forecasts G1–G2 (minor–moderate) geomagnetic storms likely around Aug. 2 driven by a coronal mass ejection that left the Sun on July 30 and earlier late‑July CMEs.
- The highest chances for visible aurora are across much of Canada with the southern edge of the auroral oval reaching northern‑tier U.S. states near the Canadian border, including Washington, Montana, North Dakota, Minnesota, Michigan and Maine.
- Summer viewing will be hampered by a near‑full moon, shorter nights and local cloud cover so faint displays may be invisible to the eye but detectable with phone night modes or long‑exposure cameras.
- Forecasts still carry uncertainty because real‑time solar wind conditions and the interplanetary magnetic field orientation (southward Bz) control strength and timing, and the UK Met Office warns the CME could deliver only a glancing impact.
- The G‑scale and Kp index (Kp ≈ 4–5 in recent forecasts) describe modest geomagnetic activity that rarely disrupts infrastructure, and skywatchers should monitor NOAA’s 30‑minute maps and aurora apps for last‑minute changes.