Aurora chasers around the world were treated to dazzling shows after a “secret” island within a coronal hole triggered an unexpected strong (G3) level geomagnetic storm overnight on Sunday (Sept. 14-15).
The outburst sent auroras spilling far beyond their usual range, thrilling aurora chasers across the U.S.
Space weather physicist Tamitha Skov explained in her latest aurora forecast on YouTube that the true culprit wasn’t the big eruptions everyone was watching, but something hidden in plain sight. “The source of the big solar storm is due to this coronal hole right here, which is a really noteworthy coronal hole for a number of reasons,” Skov said.
What made this coronal hole so unusual was a subtle, but influential magnetic twist. The coronal hole had a negative polarity that wasn’t supposed to give us big geomagnetic storms or subsequent auroras, Skov explained. But as it moved across the sun’s disk, something changed. An “island” of positive polarity appeared in the middle of the coronal hole. “That positive polarity is what ended up giving us about 6 hours worth of really intense storming,” Skov explained.
The result was a stunning aurora show. “Little things like this can really make a big difference and change a nothingburger into a G3-level solar storm,” Skov said.
Forecasts underestimated the storm
Geomagnetic storms are classified using a G-scale, which ranks their intensity from G1 (minor) to G5 (extreme). Auroras occur when solar wind interacts with Earth’s magnetic field. The charged particles from the sun collide with gases in the upper atmosphere, such as oxygen and nitrogen, transferring energy to them. This energy is released as light, producing the colorful displays seen in the night sky. The stronger the solar wind, the more dynamic and widespread the auroras can become.
Northern lights across the US (photos & videos)
The surprise solar storm delivered mesmerizing northern lights shows across the U.S.
Photographer Ross Harried captured the stunning northern lights display in the sky above Monroe, Wisconsin, U.S., on Sept. 14.
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Harried enjoyed a colorful green and purple display with vast pillars reaching high into the sky, as well as a subtle green glow as activity began to wane.
Auroras also danced above Anchorage, Alaska, U.S., on Sept. 15 during the geomagnetic storm. Photographer Hasan Akbas captured this lovely green display alongside the nearly half-lit moon.
Many aurora chasers took to X to share their stunning aurora photos during the recent geomagnetic storm.
What an #Aurora show tonight north of Casper, Wyoming (plus a bonus shot of the Milky Way)! pic.twitter.com/I2MIX6C6ZPSeptember 15, 2025
Tony Rodriguez captured striking red and green aurora pillars above Seneca Lake, New York, U.S.
“Spectacular #aurora on the southern shore of Seneca Lake in NY! The structures were visible to the naked eye. It was quite a show!” Rodriguez wrote in a post on X.
Spectacular #aurora on the southern shore of Seneca Lake in NY! The structures were visible to the naked eye. It was quite a show! pic.twitter.com/IOYbRf4iNUSeptember 15, 2025
Aurora chaser Joshua Grisewood also enjoyed the surprise aurora show from Pavilion, New York, U.S.
“Awesome surprise Aurora here in New York! Generally I am on top of these but tonight caught me off guard for sure,” Grisewood wrote in a post on X.
Awesome surprise Aurora here in New York! Generally I am on top of these but tonight caught me off guard for sure. Here is a few shots from Pavilion, NY while I finish up this exciting time-lapse!#Aurora #wxtwitter #wx #stormchasers #northernlights pic.twitter.com/vnJmgwhEuISeptember 15, 2025
Aurora chaser Colton Flint shared an incredible timelapse of the northern lights display from Massachusetts.
The footage shows just how dynamic auroras can be, with the activity appearing to ramp up out of nowhere!
Timelapse of last nights northern lights display from Massachusetts. This was one of the best ones we’ve had in the last year #mawx pic.twitter.com/3rz53oxHCRSeptember 15, 2025
Photographer Blake Brown managed to capture the show as far south as Texas.
“Northern lights made an appearance down to Texas tonight! With a lightning cameo as well,” Brown wrote in a post on X.
Northern lights made an appearance down to Texas tonight! With a lightning cameo as well. @Vincent_Ledvina #txwx @TamithaSkov #Aurora pic.twitter.com/2yMu22F8GsSeptember 15, 2025
Gabe Zago captured a truly remarkable show as auroras competed against lightning to take center stage.
“Bro this day will be impossible to beat forever,” Zago wrote in a post on X.
Bro this day will be impossible to beat forever. #ndwx #wx #Aurora #northernlight #wxtwitter pic.twitter.com/1uZzMnKEuRSeptember 15, 2025
Latest forecast
For the latest space weather outlook, and a deeper dive into what caused this surprise G3 storm, check out Skov’s full space weather forecast, available below and also on her YouTube channel.
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