G3 – Strong Geomagnetic Storm Alert issued on April 3, 2026

A G3 – Strong Geomagnetic Storm Alert was issued on April 3, 2026. The alert indicates that the geomagnetic K-index reached a value of 7 at 16:46 UTC, and the alert covers the synoptic period from 15:00 to 18:00 UTC. The warning is active and current as of 16:47 UTC.

Potential impacts are primarily expected in areas poleward of 50 degrees geomagnetic latitude. Power system operators may experience voltage irregularities, with a possibility of false alarms on some protection devices. Spacecraft may be affected by surface charging, increased drag on low Earth-orbit satellites, and potential orientation issues. Navigation systems, specifically satellite-based GPS, may see intermittent problems including loss-of-lock and increased range error. High frequency (HF) radio communications may also be intermittent. Additionally, auroras could be visible as far south as Pennsylvania, Iowa, and Oregon.

The geomagnetic activity is driven by ongoing negative polarity coronal hole high-speed stream (CH HSS) influences, as reported by NOAA SWPC. The forecast discussion notes an anticipated additional enhancement from a coronal mass ejection (CME) that departed the Sun on April 1, which may provide a glancing blow to Earth late on April 3 or early April 4.