Geomagnetic storm fuels more auroras, warnings of potential disruptions

A severe geomagnetic solar storm could bring colorful auroras to the night sky across parts of the nation for a third night in a row. 

The auroras could be seen as far south as Alabama and west to northern California, the Space Weather Prediction Center said Monday. The geomagnetic storm alert cautioned electricity providers and satellite operators the activity was more intense than expected when the warnings went out late last week.

Everything was going according to plan with the recent burst of coronal mass ejections from the Sun until late last night when things intensified and "really picked up," said Shawn Dahl, service coordinator for the Space Weather Prediction Center.

The pulsing plasma and magnetic fields erupting from solar flares on the Sun arrived "much stronger than we could have realized," Dahl said. At least five flares with ejections have been observed since Aug. 10, according to the prediction center.

Similar geomagnetic storms in May – the strongest in nearly 20 years – prompted huge excitement when people as far south as Florida and the Caribbean were able to see auroras in the night sky. The solar activity on Monday is “nowhere near as intense,” Dahl said.

The activity did, however, trigger bright, colorful auroras Sunday night across northern latitudes from Europe to Alaska, with photographers out to capture the Perseids meteor showers getting an unexpected bonus.  Auroras also were seen on Saturday night.

Adam Silverman, a space weather enthusiast from Vermont, was out with his camera on Lake Champlain Sunday night, hoping for the best. "Never in a million years when I ventured out last night did I expect to see northern lights that rivaled May 11 in vibrance and intensity – and yet that's exactly what I saw," Silverman said in an Instagram post.

"Even the most optimistic forecast for Sunday night into Monday were not suggesting this strong and this vibrant of a show," Silverman told USA TODAY. Counting Sunday, Silverman has seen an intense solar storm three times now.

"It’s one of the most magnificent night sky experiences you can dream of when you get the aurora overhead. It takes your breath away," he said. "It's jump-up-and-down exciting every time I've seen it."

Could there be auroras tonight?

It could happen, Dahl said. "Anybody who has a chance to see the aurora, especially in the North, it's worth watching our webpage to see if there's a chance of seeing the aurora."

The coronal mass ejections are strong enough that the National Oceanic and Atmospheric Administration issued a G4 warning, which grades the storms on a 1 to 5 scale similar to the scale used for hurricanes. The activity is expected to continue tonight, but Dahl said there’s a lower possibility of a G4 again tonight.

“We have no idea how long it will take for the storms to pass," Dahl said. The U.S. has one satellite a million miles from Earth that measures solar winds, he said. It can detect and measure the intensity of the ejections as they reach Earth but can’t forecast how long it will take them to pass.

How can geomagnetic storms cause problems?

They have the activity to affect technologies, such as disrupting high frequency communications, Dahl said.

The storms require power companies to more closely monitor voltage traveling in their systems because the power grid could begin to experience current on high voltage transmission lines that is not normally there, he said. “So they have to account for it.”

Utilities can handle this storm quite easily, he said. But, if the surge in voltage is not accounted for, “it can overheat transformers and cause voltage disparities.” In worst case scenarios, he said, “the surge in current could cause bulk transmission loss over an extensive geographical area.”

Forecasters at the center activated the North American Reliability Corporation Hotline to keep power grid operators informed of the ongoing activity, NOAA said.

How do the solar storms affect satellites?

With a warning like this one, the center is letting satellite operators know they must work to maintain the proper orbital positions, Dahl said.

Ejections can increase the density of the atmosphere they’re flying in, Dahl said. That exposes satellites in low orbit around the earth to drag, “and in worst case scenarios, they could burn up in the atmosphere if they don’t continue their orbit properly.”

With more satellites in orbit, he said, “many industries are learning that they have to account for this and plan and be ready to maintain their satellites’ operational capacity.”

Why are the geomagnetic storms appearing?

We are in a period known as solar maximum, in an 11-year cycle of the sun when increased solar activity erupts.

Every 11 years or so, the Sun’s magnetic field flips completely, with the Sun’s north and south poles switching places, according to the National Aeronautics and Space Administration. Solar maximum happens in the middle of the cycle.

Solar maximum:Sun expected to bring auroras more often through 2025

Space weather activity and things like this are more likely to happen through the remainder of 2024, through 2025 and even into 2026, Dahl said.

Dinah Voyles Pulver covers climate and the environment for USA TODAY. Reach her at dpulver@gannett.com or @dinahvp.