G1 – Minor Geomagnetic Storm Alert issued on October 30

A G1 – Minor Geomagnetic Storm Alert was issued on October 30, 2025. The alert is based on the Geomagnetic K-index reaching a value of 5, with the threshold reached at 10:12 UTC. The alert covers the synoptic period from 09:00 to 12:00 UTC, according to the NOAA Space Weather Prediction Center.

Potential impacts from this G1 – Minor event are expected primarily poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations can occur, and there may be minor impacts to satellite operations. Aurora may be visible at high latitudes, including locations such as northern Michigan and Maine in the United States.

The event was triggered by enhanced solar wind conditions resulting from the influence of a positive polarity coronal hole high-speed stream (CH HSS). Solar wind speeds increased and the geomagnetic field was observed at unsettled and active levels in the 24-hour summary. G1 – Minor geomagnetic storming remains likely into the early hours of October 30 under continued CH HSS effects.