A severe "geomagnetic storm" could take place this weekend, the National Weather Service's Space Prediction Center said. According to the agency, its the first time in nearly 20 years officials warned of such an event.
The watch comes after multiple earth-directed coronal mass ejections (CME’s) were observed by forecasters this week.
CME’s are "large expulsions of plasma and magnetized particles from the Sun’s corona," according to the SWPC. Those ejections can expand in size as they approach Earth, and can cause geomagnetic storms when they arrive.
"Several strong flares have been observed over the past few days and were associated with a large magnetically complex sunspot cluster, which is 16 times the diameter of Earth," the agency said in a tweet. "Additional solar activity is expected from the region."
At least five CME’s were observed in recent days, the agency said, noting the particles could begin arriving to Earth "as early as midday Friday."
It’s expected that the CME’s could continue to arrive through Sunday, marking for an “unusual event.”
Local
Only three “severe” geomagnetic storms have been observed since the current solar cycle began in Dec. 2019. The last G4 storm hit Earth in March, and the last G5 storm hit in Oct. 2003, causing power outages in Sweden, according to SWPC.
Officials with the agency will hold a media availability at 9 a.m. CST Friday to discuss the conditions and potential impacts of a "severe solar storm."
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What happens during a geomagnetic storm?
In a geomagnetic storm, the particles ejected by the sun cause disturbances in Earth’s magnetosphere. Particularly strong storms can impact the Earth’s ionosphere, adding energy in the form of heat that can “increase the density and distribution of density in the upper atmosphere, causing extra drag on satellites in low Earth orbit,” according to the SWPC.
As a result, disruptions in navigation systems, radio communications and power grids are all possible, though it is unclear if the approaching storm will be strong enough to yield those impacts.
Another potential impact that could occur is a much-more vibrant Northern Lights spectacle, which could be seen as far south as Tennessee or even Alabama late Friday and into Saturday, according to officials.
Unfortunately for residents in Illinois, showers are expected to impact the Chicago area late Friday and into Saturday, likely spoiling the show that evening.
In addition, space weather forecasts can change dramatically in a matter of hours, with officials providing additional updates as the weekend draws closer.
