Overview
- NOAA’s Space Weather Prediction Center expects a full-halo CME from an M8.1 flare in Region 4299 to reach Earth early to midday on December 9, with strong geomagnetic storming possible.
- Auroras could push far south of normal, with viewlines suggesting visibility from the northern tier into the lower Midwest and Oregon, potentially covering up to 22 U.S. states.
- Potential effects include degraded GPS accuracy, intermittent HF radio issues, satellite anomalies, and voltage irregularities on high-latitude power systems, with operators monitoring conditions.
- Forecast guidance points to Kp values near 7 during G3 conditions after earlier Kp 5 readings, though exact timing and intensity remain uncertain and will be updated in real time.
- The U.K. Met Office has also issued a G3 watch, and skywatchers are advised to seek dark, north-facing horizons and follow NOAA’s short-term aurora updates as the event approaches.