G1 – Minor Geomagnetic Storm Alert issued on June 11

A G1 – Minor Geomagnetic Storm Alert was issued on June 11, 2026. The alert was announced at 20:40 UTC and is valid for the synoptic period from 18:00 to 21:00 UTC. The NOAA Space Weather Prediction Center has classified this event under the G1 – Minor category.

The area of impact is primarily poleward of 60 degrees geomagnetic latitude. Potential impacts include weak power grid fluctuations and minor effects on satellite operations. Aurora may be visible at high latitudes, such as in the northern tier of the United States, including regions like northern Michigan and Maine.

This alert was triggered as a corotating interaction region (CIR) preceded the onset of a negative polarity coronal hole high speed stream (CH HSS), resulting in enhanced solar wind conditions. Active to G1 – Minor geomagnetic storm levels are expected to persist, with the high-speed stream and additional influences from coronal mass ejections that departed the Sun on June 9 and 11 contributing to the geomagnetic activity.