G1 – Minor Geomagnetic Storm Alert issued on October 11

A G1 – Minor Geomagnetic Storm Alert was issued on October 11, 2025, after the geomagnetic K-index reached a value of 5 at 08:59 UTC. The alert, issued at 09:02 UTC, applies to the synoptic period from 06:00 to 09:00 UTC, and signifies active warning conditions.

The area of impact is expected to be primarily poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations may occur due to induced currents, and minor impacts on satellite operations are possible. Aurora could be visible at high latitudes, including the northern tier of the U.S. such as northern Michigan and Maine.

According to the latest forecast discussion, the geomagnetic field is responding to an anticipated onset of influence from a recurrent, negative polarity coronal hole high-speed stream (CH HSS). This condition is expected to cause active geomagnetic levels, including G1 – Minor storm levels, through October 13, 2025.