G1 – Minor Geomagnetic Storm Alert issued on October 31

A G1 – Minor Geomagnetic Storm Alert was issued on October 31, 2026, following an observed geomagnetic K-index of 5. The alert covers the synoptic period from 18:00 UTC to 21:00 UTC and was released by the NOAA Space Weather Prediction Center at 19:07 UTC.

According to the alert, impacts are primarily expected poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations may occur due to induced currents. Minor operational impacts are possible for spacecraft. There is also the potential for aurora sightings at high latitudes, such as the northern tier of the United States, including northern Michigan and Maine.

The triggering event for this geomagnetic activity is enhanced solar wind from a positive polarity coronal hole high-speed stream (CH HSS). Solar wind parameters saw an increase, with speeds reaching up to 440 km/s and total magnetic field strength peaking at 11 nT. No Earth-directed coronal mass ejections were observed at this time.