Sun releases the largest solar radiation storm ‘in over 20 years,’ forecasters say

It could also disrupt satellite-based communications and GPS accuracy.

A solar radiation storm, ranked at a level four out of five on a severity scale, is being tracked by the National Weather Service’s Space Weather Prediction Center, or SWPC.

“An S4 severe solar radiation storm is now in progress - this is the largest solar radiation storm in over 20 years,” SWPC shared on X, formerly known as Twitter. “The last time S4 levels were observed was in October, 2003. Potential effects are mainly limited to space launch, aviation, and satellite operations.”

The Halloween space weather storms of October 2003 resulted in power outages in Sweden and damages to power transformers in South Africa, according to SWPC.

When solar radiation storms reach Earth, they can increase radiation exposure risks for astronauts in low-Earth orbit, such as those aboard the International Space Station, as well as for passengers on flights traveling polar routes.

SWPC has notified airlines, NASA, the Federal Aviation Administration, the Federal Emergency Management Agency, the North American Electric Reliability Corporation, and other operators to prepare for the storm.

“We’ve been making all these phone calls to ensure that we are keeping all the critical technological infrastructure operators in the know of what’s happening,” said SWPC forecaster Shawn Dahl.

During increased radiation risk events, astronauts can move to parts of the space station that are better shielded, as they did during previous solar storms, such as the extreme geomagnetic storm in May 2024.

Heightened radiation can also pose risks to satellites we rely on for communications and navigation.

During the May 2024 geomagnetic storm, tractor company John Deere reported that some customers reliant on GPS for precision farming experienced a disruption. But for the most part, power grid and satellite operators kept satellites in order and properly in orbit and managed the buildup of intense geomagnetic currents on the grid systems.

While satellite operators will likely need to take action Monday night, widespread technology impacts for the general public are not expected, said Ryan French, a solar physicist at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder.

Anticipating auroras

A severe geomagnetic storm also reached Earth Monday at 2:20 p.m. ET, Dahl said. Such storms also have the ability to disrupt the electric power grid, according to SWPC.

While a solar radiation storm marks the release of intense, rapidly-moving charged particles toward Earth, slower-moving geomagnetic storms are caused by coronal mass ejections (CMEs), or explosions of plasma and magnetic fields from the sun’s outer atmosphere.

When these outbursts are directed at Earth, they can cause major disturbances of Earth’s magnetic field, resulting in geomagnetic storms.

The coronal mass ejection, which launched from the sun on Sunday, was triggered by an X-class flare, the most intense type of solar flare. This marks the first major solar flare of the year, French said.

Increased solar activity causes auroras that dance around Earth’s poles, known as the northern lights, or aurora borealis, and southern lights, or aurora australis. When the energized particles from coronal mass ejections reach Earth’s magnetic field, they interact with gases in the atmosphere to create different colored lights in the sky.

Auroras may be visible over much of the northern half of the US, and potentially as far south as Alabama and northern California, according to SWPC.

Parts of the Midwest, including much of Minnesota, will have clear skies for aurora viewing, said CNN Meteorologist Chris Dolce.

“Clouds might clear enough by tomorrow early AM over northern Illinois and Wisconsin to possibly see, too,” Dolce said. “The Pacific Northwest might have decent conditions west of the Cascades. The Northeast is a mix. The interior looks pretty cloudy, but conditions closer to the coast might clear out enough to make it visible late tonight and early tomorrow.”

Even if the colorful displays don’t seem apparent to the naked eye, sensors in cameras, including cell phone cameras, can pick them up.

“For aurora chasers, your best bet is to find somewhere with a clear and dark view north, without interference from light pollution,” French said. “Aurora will likely be strongest as soon as it is dark enough to see them at your location.”

Auroras experience short 20-minute bursts of activity called substorms. During these periods, the northern light are visible much further south than during the rest of the night, French said.

More flares from an active sunspot region are possible, and any occurring within the next week have a good chance of producing further Earth-directed eruptions, French said.