G1 – Minor Geomagnetic Storm Alert issued on October 4

A G1 – Minor Geomagnetic Storm Alert was issued on October 4, 2026. The alert was triggered when the geomagnetic K-index reached 5 at 11:22 UTC. This alert is valid for the synoptic period from 09:00 UTC to 12:00 UTC, according to the NOAA Space Weather Prediction Center.

Potential impacts from this event are expected primarily poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations can occur as a result of induced currents. Satellite operators may experience minor impacts on satellite operations. Additionally, auroras may be visible at high latitudes, potentially reaching as far south as the northern tier of the United States, including areas such as northern Michigan and Maine.

The alert follows enhanced solar wind conditions caused by the influence of a coronal hole high-speed stream (CH HSS). Forecasts suggest that active geomagnetic conditions and G1 – Minor storm levels are likely on October 4, with ongoing influence continuing into October 5 and 6 as CH HSS effects gradually diminish. No significant solar flares or Earth-directed coronal mass ejections were observed preceding this event.