Lady Aurora’ Dances Across U.S., May Offer A 2nd Act This Weekend

“Lady Aurora,” as the aurora borealis is sometimes called, didn’t disappoint Thursday, putting on a colorful sky show seen across the continental U.S. that could repeat Friday night and, in some far northern parts of the country, again on Saturday.

The geomagnetic storm that sent the aurora borealis far south Thursday has subsided from a “severe” G4- to a “strong” G3-level storm. The current aurora map from the Space Weather Prediction Center, a division of the National Oceanic and Atmospheric Administration, shows the oval aurora may be seen as far south as northern Iowa.

The aurora could again be visible Saturday in the northern half of Minnesota and other northern-tier states.

On Friday, the SWPC said a K-Index of 7 or greater is expected to persist through Friday. Generally, the K number, a measure of the aurora’s strength, needs to be at least 5 for the aurora to be visible.

The amazing display of northern lights Thursday was witnessed by millions of people around the world, including in places such as Capetown, South Africa. Aurora chasers flooded social media with photos of the pink, red, purple, green and yellow lights.

For only the second time in two decades, NOAA issued a severe geomagnetic storm watch Wednesday after the sun fired off a strong X-class solar flare and coronal mass ejection carried to Earth by exceptionally fast solar winds. CMEs are large explosions of plasma and magnetized particles from the sun’s corona that can expand in size as they approach Earths’ atmosphere.

The X1-flare that set off this week’s display isn’t nearly as strong as the X8.7 flare in May that made the aurora visible in areas along the southern U.S. border, or the more recent even stronger X9 flare that produced northern displays in about a third of the country this week.

The difference, space weather forecaster Shawn Dahl explained in a briefing with reporters Wednesday, is that it was a long-duration solar flare that erupted from the center of the sun and is being carried to Earth by extremely fast at 2.5 million miles per hour.

Mike Bettwy, the head of the SWPC’s forecast office, said aurora chasers are usually rewarded within a couple of hours after nightfall. Patience is a key, he said.

“The key is the magnetic orientation,” he said. “It’s remarkable how quickly the aurora can shut down and diminish, and just as quickly return.”

If the aurora doesn’t materialize this time around, there are plenty more chances for people to see them. Solar Cycle’s 25 solar maximum may not occur until early 2025, and even 2026 could be a busy year for solar activity.

Activity this solar cycle has surprised space weather scientists and forecasters. Solar Cycle 25 is the most active on record, and they’re not quite sure why.

“It’s one of the many mysteries to unravel,” Dahl said.

For many of those who saw the aurora Thursday, it was a once-in-a-lifetime experience.

In Massachusetts, Nick Walker posted photos of a once-in-a-lifetime experience on the social media platform X, noting he has “never experienced anything like this!”