Overview
- NOAA’s Space Weather Prediction Center expects the CME to arrive early to midday on December 9 with periods of G3 (strong) storming possible.
- Forecasts indicate Kp could peak near 7, which may bring aurora visibility to as many as 22 U.S. states from the Pacific Northwest across the Upper Midwest and Northeast.
- Forecasters highlight significant uncertainty in exact arrival time and intensity, with the auroral reach depending on real-time Bz measurements.
- SWPC cautions that strong geomagnetic activity can cause limited disruptions to HF radio, GPS accuracy, satellites and localized power systems.
- Best viewing is in dark, north-facing locations before dawn or after dusk with clear skies, and skywatchers should monitor SWPC updates as the Geminids approach later this week.