G1 – Minor Geomagnetic Storm Watch issued for April 17, 2026

A G1 – Minor Geomagnetic Storm Watch was issued by NOAA SWPC for April 17, 2026. The Watch indicates expected geomagnetic activity reaching G1 – Minor and G2 – Moderate storm levels, with the highest predicted storm level reaching G2 on April 17 and 18, and G1 – Minor on April 19. This watch supersedes any previous watches that may have been in effect.

Potential impacts during this period include weak power grid fluctuations primarily at locations poleward of 60 degrees geomagnetic latitude. Satellite operations might experience minor impacts. Aurora displays could become visible at high latitudes, including the northern tier of the United States such as northern Michigan and Maine. These impacts fall within the typical range for G1 – Minor and G2 – Moderate geomagnetic storms as defined by official NOAA space weather scale descriptions.

According to the latest forecast discussion by NOAA SWPC, the trigger for this watch is the anticipated arrival of a co-rotating interaction region followed by negative polarity coronal hole high-speed stream (CH HSS) activity. This enhanced solar wind environment is expected to bring unsettled to active geomagnetic conditions, making G1 – Minor to G2 – Moderate geomagnetic storming likely from April 17 into April 18, 2026.