A coronal mass ejection that spewed from the Sun on Friday reached Earth over the weekend, resulting in severe geomagnetic storm conditions. Though the storm is still active as of Monday afternoon, the National Oceanic and Atmospheric Administration (NOAA) says conditions are diminishing.
The NOAA Space Weather Prediction Center shared via X Friday evening that a moderate solar flare was building strength in Region 3614, a sunspot cluster on the surface of the Sun. The flare quickly jumped from an R2/M5 classification (meaning it was capable of moderate radio blackouts) to an R3/X1, signaling the potential for severe communication disruptions. Within a few minutes, a second flare burst from Solar Region 3615, another sunspot group.
Solar flares and coronal mass ejections (CMEs) often go hand in hand, and this weekend was no exception. Using an open-source solar visualization software produced by NASA and the European Space Agency, the NOAA spotted a full halo CME spewing from the Sun's surface. When a CME appears to erupt from all sides of the Sun (hence the "full halo" moniker), it means the ejection is headed toward the viewer—in this case, toward us here on Earth.
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As CMEs travel through space, they carry a cloud of charged particles and magnetic fields. These disrupt solar wind patterns up to an hour before reaching Earth, where they cause disruptions across the part of the magnetosphere that faces the Sun. Such disruptions manifest in the form of what we call geomagnetic storms.
Friday's CME reached Earth on Sunday, kicking off G2 (moderate) and G3 (strong) geomagnetic storm conditions. Though storm warnings were in place, the NOAA assured the public that it "need not be concerned." The most noticeable effects would likely be a stretched aurora borealis and slight communication delays. Hours later, the storm escalated to the NOAA's G4 (severe) classification, earning it a "possible voltage control problems" warning with potential "effects to satellite operations." The agency now expects the aurora borealis to be visible across the northern half of the United States tonight, March 25.
Satellite anomalies or GPS disruptions can always arise during a geomagnetic storm, and the NOAA says infrastructure operators have been notified accordingly. But this weekend's storm appears to be losing steam. Now at a G2 classification once again, the storm is unlikely to produce the types of disruptions expected during a severe geomagnetic event.
