G1 – Minor Geomagnetic Storm Watch issued for August 12, 2026

A G1 – Minor Geomagnetic Storm Watch was issued for August 12, 2026. This Watch, released by NOAA SWPC on August 9 at 13:38 UTC, supersedes all previous watches in effect. The highest storm level predicted is G1 – Minor on August 12, with storm levels remaining below G1 on August 10 and 11.

Potential impacts of a G1 – Minor geomagnetic storm primarily affect regions poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations may occur, and minor impact on satellite operations is possible. Auroras may be visible at high latitudes, such as the northern tier of the United States, including northern Michigan and Maine.

According to the latest forecast discussion, two recent filament eruptions on the Sun are responsible for the anticipated geomagnetic activity. The first eruption, observed early on August 8, produced a coronal mass ejection (CME) with a predicted arrival at Earth either very late on August 11 or early on August 12. The second eruption is expected to interact with the initial CME and a corotating interaction region, potentially contributing to geomagnetic storm conditions on August 12. Solar activity remains at very low levels otherwise.