Coronal mass ejection (CME) produced by X1.8 solar flare on October 9 impacted Earth at 15:15 UTC on October 10, triggering a G3 – Strong geomagnetic storm.
According to the SWPC, the storm could affect ongoing recovery efforts for hurricanes Helene and Milton in key areas. Communication systems reliant on low-Earth orbit satellites and high-frequency communications may experience disruptions. Power grids, already stressed from the hurricanes, could face additional strain, while GPS services, crucial for disaster relief operations, may be degraded.
The Space Weather Prediction Center (SWPC) has already informed FEMA and state agencies involved in recovery efforts of the potential impacts. If weather conditions are clear, the aurora could be visible tonight as far south as Alabama and northern California.
G4 – Severe level is still considered likely and there is also a slight chance of a G5 – Extreme storm based on early assessments of the CME’s intensity.
Potential impacts of G4 – Severe geomagnetic storms are primarily expected poleward of 45 degrees Geomagnetic Latitude. Power grids may experience widespread voltage control issues, and protective systems could mistakenly trip key assets, while induced pipeline currents may intensify.
Spacecraft systems could face surface charging, increased drag on low Earth orbit satellites, and issues with tracking and orientation. Satellite navigation (GPS) may be degraded or inoperable for hours, and HF (high frequency) radio propagation could be sporadic or blacked out. Auroras may be visible as far south as Alabama and northern California.
Geomagnetic activity can vary considerably during storm progression with intermittent periods of escalation or weakening as the major disturbance in the solar wind continues.
Meanwhile, the S3 – Strong solar radiation storm, which began at 12:30 UTC yesterday due to the X1.8 solar flare, has now dropped below the S3 threshold.
Potential impacts of S3 radiation storms include increased radiation exposure for passengers and crew on high-altitude, high-latitude flights, as well as elevated radiation risks for astronauts conducting extra-vehicular activities.
Spacecraft may experience single-event upsets to satellite operations, noise in imaging systems, and slight reductions in solar panel efficiency.
Additionally, polar HF (high frequency) radio propagation could be degraded or experience episodic blackouts.
References:
1 Major X1.8 solar flare produces Earth-directed CME, impact expected late October 10 – The Watchers – October 9, 2024
2 Strong solar radiation in progress, severe geomagnetic storm watch in effect – The Watchers – October 9, 2024
3 CME Arrival at Earth has Occurred and Warnings have been Issued – SWPC – October 10, 2024