G1 – Minor Geomagnetic Storm Watch issued for October 19 and 20, 2026

A G1 – Minor Geomagnetic Storm Watch was issued for October 19 and 20, 2026. The Watch, released on October 18, 2026, by NOAA’s Space Weather Prediction Center, forecasts minor geomagnetic storm conditions, with the greatest risk during late October 19 into October 20. No further alerts are currently in effect for October 21, 2026, as storm levels are expected to drop below G1.

Potential impacts primarily affect areas poleward of 60 degrees geomagnetic latitude. Weak fluctuations in power grids are possible, and minor impacts may occur on satellite operations. High-latitude auroras may be visible, including in the northernmost regions of the United States such as northern Michigan and Maine.

This Watch has been prompted by anticipated effects from a positive polarity coronal hole high speed stream (CH HSS) expected to become geoeffective late on October 19 and continue through October 20. Solar activity remains at low levels, with no Earth-directed coronal mass ejections observed.