G1 – Minor Geomagnetic Storm Watch issued for October 21, 2026

A G1 – Minor Geomagnetic Storm Watch was issued for October 21, 2026. This Watch, released by NOAA’s Space Weather Prediction Center at 19:12 UTC on October 20, 2026, indicates that minor geomagnetic storm conditions (G1) are predicted for October 21. The Watch supersedes all prior watches in effect. No geomagnetic storm levels are forecast for October 22 and October 23, with expected conditions below G1 on those days.

Potential impacts are mainly expected poleward of 60 degrees geomagnetic latitude. Weak power grid fluctuations may occur due to induced currents. A minor impact on satellite operations is possible, and auroras could be visible at high latitudes, such as the northern tier of the United States, including areas like northern Michigan and Maine. These impacts are characteristic of a G1 – Minor event according to NOAA’s classification.

The predicted geomagnetic activity is associated with the anticipated arrival of a positive polarity coronal hole high speed stream (CH HSS). Solar wind enhancements linked to this CH HSS are expected to raise geomagnetic field levels to G1 (Minor) late on October 20, with active storm conditions likely on October 21 before easing by October 22. No Earth-directed coronal mass ejections (CMEs) were observed in recent solar observations.