G2 – Moderate Geomagnetic Storm Watch issued for August 28, 2026

A G2 – Moderate Geomagnetic Storm Watch has been issued for August 28, 2026. The watch, released by NOAA SWPC at 18:38 UTC on August 25, 2026, highlights expected geomagnetic activity due to a High-Speed Stream (HSS) on August 27 and Coronal Mass Ejections (CMEs) on August 28. The highest storm level predicted by day is below G1 on August 26, G1 – Minor on August 27, and G2 – Moderate on August 28. This announcement supersedes all prior watches in effect.

According to NOAA, the primary area of impact will be poleward of 55 degrees Geomagnetic Latitude. Potential impacts include possible power grid fluctuations and voltage alarms in high-latitude power systems, satellite orientation irregularities, and increased drag on low Earth-orbit satellites. HF (high frequency) radio propagation may experience fading at higher latitudes. The aurora may become visible as far south as New York, Wisconsin, and Washington state.

The watch is informed by recent solar activity, specifically multiple M-class solar flares from Region 4513. Notably, an M6.9 flare peaked at 10:02 UTC on August 25, 2026, accompanied by radio and Type II sweeps, indicating a subsequent CME. The forecast calls for continued moderate solar activity from Region 4513 and enhanced solar wind expected by late August 27, potentially triggering geomagnetic disturbances leading up to the G2 storm level on August 28.