G2 – Moderate Geomagnetic Storm Watch issued for May 15, 2026

A G2 – Moderate Geomagnetic Storm Watch was issued for May 15, 2026, by NOAA’s Space Weather Prediction Center. This Watch forecasts that the geomagnetic storm level may reach G2 – Moderate on May 15, followed by G1 – Minor level activity on May 16 and May 17, 2026. The alert supersedes any previous Watches in effect.

Potential impacts from this geomagnetic storm may be primarily experienced poleward of 55 degrees geomagnetic latitude. Power grid fluctuations can occur, and high-latitude power systems may experience voltage alarms. Satellite operators may observe orientation irregularities, and there could be increased drag on low Earth-orbit satellites. High frequency (HF) radio propagation can fade at higher latitudes, and aurora may be visible as far south as New York, Wisconsin, and Washington state.

According to the latest SWPC forecast discussion, the expected geomagnetic activity is likely driven by the anticipated arrival of a corotating interaction region (CIR) associated with a negative polarity coronal hole high-speed stream (CH HSS) near Earth on May 15. Lingering effects from this CH HSS are likely to maintain active to G1 – Minor storm levels through May 16 and 17, 2026. No Earth-directed coronal mass ejections (CMEs) have been observed.