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

A G2 – Moderate Geomagnetic Storm Watch was issued at 16:36 UTC on August 26, 2026, by NOAA’s Space Weather Prediction Center. The watch indicates that G2 – Moderate geomagnetic storm conditions are expected on August 28 and August 29, following G1 – Minor conditions forecast for August 27. This watch supersedes any prior watches in effect.

Potential impacts of the forecasted geomagnetic storms include power grid fluctuations, especially at high latitudes, and possible voltage alarms in high-latitude power systems. Spacecraft operators may experience satellite orientation irregularities and increased drag on low Earth-orbit satellites. HF radio propagation can fade at higher latitudes, and auroras may be visible as far south as New York, Wisconsin, and Washington state. The area of greatest impact is expected to be poleward of 55 degrees geomagnetic latitude.

The watch was triggered by an anticipated combination of a high-speed solar wind stream (HSS) expected to arrive on August 27 and coronal mass ejections (CMEs) set to impact on August 28 and 29, according to the latest forecast discussion. The forecast also notes that solar activity reached moderate levels, with activity primarily associated with solar region 4513.