The aurora borealis will likely be visible throughout Vermont the night of Saturday, Oct. 5, according to a forecast by the Space Weather Prediction Center.
Eric Myskowski, a meteorologist at the National Weather Service Burlington office, said the forecast Saturday is mostly clear skies with cloudy skies in the Northeast Kingdom, though there will be breaks in the clouds. He advised prospective aurora viewers to find dark places with a clear view of the northern horizon.
“Basically, get away from light pollution, as far as you can. Say you live in Burlington, it would be ideal to get outside the city area and to the northern horizon,” Myskowski said. “Where you have a visible northern horizon is better.”
A weaker aurora may also be visible in just the northern part of the state on Friday night, but Myskowski said to expect cloudy skies clearing out closer to the early morning.
Auroras form when charged particles from the sun enter the Earth’s magnetic field, deflecting them towards the geomagnetic poles (which don’t quite align with the North and South Poles). There, the particles collide with oxygen and nitrogen atoms, causing them to emit light. When an aurora appears in the northern hemisphere, it’s referred to as aurora borealis, or the northern lights.
Larger auroras like the ones expected Friday and Saturday are caused by geomagnetic storms, which occur when the Earth’s magnetosphere is disturbed by an explosion of charged particles from the sun, said Shawn Dawl, service coordinator for the Space Weather Prediction Center, part of the National Oceanic and Atmospheric Administration.
There were two powerful solar flares on the sun this week. One measured an X9.0, the strongest on record since 2017. Those two solar flares coincided with two coronal mass ejections, a related but separate event where plasma and magnetic fields explode from the sun’s corona.
While the electromagnetic radiation from a solar flare reaches the Earth in minutes, the particle clouds released by coronal mass ejections take longer — and it’s the interaction between these clouds and the Earth’s magnetosphere that produce a geomagnetic storm.
Dahl said the Space Weather Prediction Center had low confidence in the first coronal mass ejection hitting Earth on Friday, but fair confidence on the second one, which it estimates will cause a G3-level geomagnetic storm. The storm in May which covered a larger portion of the U.S. measured at a G4.
And this won’t be the last big geomagnetic storm of the next few years. The sun is currently in an active period of the 11-year solar cycle, though Dahl noted it isn’t yet clear if we’re at the peak of solar activity.
“Solar cycles don’t just reach the peak and then stop. They reach the peak and they slowly come down,” Dahl said. “So all of this year, all of next year, even well into 2026 we’ll still be at an elevated risk for space weather storms such as what we might see this weekend.”
Have questions, comments or tips? Send us a message. Or contact the reporter directly at corey.dockser@vermontpublic.org.
