G4 – Severe geomagnetic storm in progress

A coronal mass ejection (CME) produced on June 25, 2024, impacted Earth shortly after 09:30 UTC on June 28, producing G4 – Severe geomagnetic storm.

At 09:12 UTC, the ACE satellite observed an IP shock passage, likely influenced by the CME produced on June 25, leading to enhanced solar wind parameters.

The geomagnetic field reacted with G1 – Minor storming beginning at 11:25 UTC, escalating to G2 – Moderate storm by 11:47 UTC, and further intensifying to G4 – Severe by 14:18 UTC.

Severe geomagnetic storms (G4) occur about 100 times per solar cycle, primarily impacting areas poleward of 45 degrees Geomagnetic Latitude.

Potential impacts include widespread voltage control problems and erroneous tripping of key assets from the power grid due to induced currents, intensified pipeline currents, surface charging on spacecraft, increased drag on low Earth orbit satellites, and tracking and orientation issues.

During G4 – Severe geomagnetic storm, satellite navigation (GPS) may be degraded or inoperable for hours, HF radio propagation can become sporadic or blacked out, and auroras may be visible as far south as Alabama and northern California.

According to the NOAA/SWPC Forecast Discussion published at 12:30 UTC today, unsettled to G2 – Moderate storming is expected on June 28, with G1 – Minor storming likely to continue through early on June 29.

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If you captured any images of today’s auroras, we invite you to share them with us.

References:

¹ Forecast Discussion – NOAA/SWPC – Issued at 12:30 UTC on June 28, 2024

Featured image credit: Thomas Madey (via SpaceWeather). Image taken on June 27, 2024 at Claverack, NY