A powerful solar storm could trigger auroras farther south over the US than usual

A powerful solar storm is expected to reach Earth on Monday evening, potentially triggering a display of northern lights across the northern hemisphere.

The stunning wave of auroras may be visible much farther south than is typical, reaching not just the northern US states but also parts of the lower Midwest and Oregon, according to a statement from the US National Oceanic and Atmospheric Administration’s Space Weather Prediction Center.

Scientists rank space weather conditions on a scale of five, from minor (G1) to severe (G5), and Monday night’s forecast shows the geomagnetic storm will likely cause moderate, G2- or G3-level conditions early in the night. And the storm may reach a rare G4 designation going into Tuesday morning, according to the UK’s Meteorological Office.

A map of the storm’s view line shows dazzling auroral displays could stretch as far south as upper Oregon, Idaho, Wyoming, Nebraska, Iowa, Illinois, upstate New York and northern New England.

The UK’s Met Office added that auroras “may be visible across much of the UK, potentially without the need for photographic equipment,” especially if skies are dark and cloudless.

“However, a waxing gibbous Moon may hinder visibility in some areas,” the agency added.

What causes auroras

The light shows are the result of a coronal mass ejection, or CME, which occurred on Saturday. During the CME, large clouds of ionized gas, called plasma, and magnetic fields erupted from the sun’s outer atmosphere and were sent to space at high speeds, with NOAA estimating 2 million miles per hour.

The material is expected to reach Earth on Monday evening and peak around 2 a.m. to 5 a.m. Eastern time on Tuesday.

When the solar particles from the CME reach Earth, they can collide with atoms and molecules in the upper atmosphere, causing some elements to glow in varying hues. Oxygen, for example, gives off a green cast, while nitrogen is illuminated in shades of blue and purple.

Although space weather forecasters are not tracking another CME headed for Earth, the sun is in the midst of a stretch of usually high activity called the “solar maximum.” This year marks the apex in an 11-year cycle of activity, which means more solar storms and gorgeous auroras could be on the way soon.

Several geomagnetic storms have already caused notable northern light displays over the past year, including one in May 2024 and a particularly strong storm in October.

“This CME is very Earth-directed, but that doesn’t mean it will pack a punch like storms from last year or even earlier this year,” Shawn Dahl, a space weather forecaster at NOAA’s Space Weather Prediction Center, told CNN.

Dahl added that, although NOAA forecasters did not issue a G4 “watch” like its counterpart in the UK did, “we think there is a chance for G4 if the CME magnetic field is strong enough and favorable — but we won’t know that until it arrives 1 million miles from Earth at our solar wind observatory.”

The Space Weather Prediction Center estimates the CME will hit the 1-million-mile mark about 20 to 50 minutes before it arrives at Earth “late afternoon EDT.”

In addition to northern light displays, such activity can also create minor technological disturbances including GPS satellite disruptions, radio signal interferences and power grid interruptions .

NOAA said “limited, minor effects to some technological infrastructure (are) possible, but usually mitigatable” with the moderate-to-strong solar storm expected to roll through Monday night.

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