G1 – Minor Geomagnetic Storm Alert issued on September 8

A G1 – Minor Geomagnetic Storm Alert was issued on September 8, 2026 after the geomagnetic K-index reached a value of 5 at 17:44 UTC. The alert is valid for the synoptic period from 15:00 to 18:00 UTC. According to the NOAA Space Weather Prediction Center, a warning remains active as geomagnetic storm conditions persist.

According to the official notification, the primary area of impact is poleward of 60 degrees geomagnetic latitude. Potential effects include weak fluctuations in power grids, minor impacts on spacecraft operations, and the possibility of auroral displays at high latitudes. Aurora may be visible in the northern tier of the U.S., such as northern Michigan and Maine, under these storm conditions.

This G1 – Minor Geomagnetic Storm was triggered mainly by the continued influence of a positive polarity coronal hole high speed stream. Solar wind parameters reached peaks of 16–17 nT with extended southward IMF deflections and wind speeds approaching 580–600 km/s. Further enhancements are expected from coronal mass ejections (CMEs) that left the Sun on September 5 and 6, 2026, contributing to ongoing geomagnetic disturbances.