Overview
- The Space Weather Prediction Center expects a full-halo CME from an M8.1 flare on December 6 to reach Earth early to midday on December 9 with potential periods of G3 storming.
- A Kp index near 5 was forecast for Sunday night, signaling increased auroral activity that could extend farther south than usual ahead of the main arrival.
- OVATION guidance points to the best viewing odds across Alaska and the northernmost parts of Washington, Idaho, Montana, Wyoming, the Dakotas, Minnesota, Wisconsin, Michigan, northern New York, Vermont, New Hampshire and Maine.
- Officials warn of possible minor effects on power systems, communications, GPS and satellites from Tuesday into Wednesday as geomagnetic conditions intensify.
- Forecasters will update timing and severity as real-time measurements clarify the CME’s magnetic orientation, which will determine how widespread auroras and impacts become.