“Severe” Solar Storm Might Bring Northern Lights to the Deep South

A “severe” geomagnetic storm tore through the heliosphere on September 13 and 14, according to NOAA’s Space Weather Prediction Center, and might make the northern lights visible as far south as Alabama in the coming days.

The agency issued an alert on September 17 warning that the two coronal mass ejections (CMEs) observed over that weekend could cause potential disruptions to Earth’s power grid, navigational satellites, and high frequency radio. But in good news for skywatchers, the storm may cause skies to glow green, pink, or purple across the northern half of the lower 48 states.

Geomagnetic storms are disturbances in Earth’s magnetosphere caused by CMEs and solar winds. These winds carry charged particles from the sun, which interact with gasses in Earth’s atmosphere and give off different colors of light around the North and South Poles. Usually, the northern lights can only be observed from within the auroral oval, an area that encompasses the Arctic regions of Scandinavia, Russia, Alaska, and Canada. 

Especially powerful geomagnetic storms can push these particles into the lower latitudes: after a G5 storm, the most severe level, in May 2024, people observed the northern lights in Oklahoma and Florida. During November 2023, the aurora borealis was observed as far south as the Netherlands, far removed from the Arctic circle, much to the surprise of many of its citizens.

Contrary to what its consistent appearance from Earth would suggest, the surface of the sun is an incredibly dynamic environment. It moves through 11-year solar cycles in which eruptions of radiation (in the form of CMEs or solar flares) shoot out from the star’s core at higher frequency and with greater intensity, traveling across space and interacting with Earth’s magnetosphere. 

This interaction not only creates the phenomenon we know as the northern lights, but can also lead to power outages and radio blackouts. The Space Weather Prediction Center’s alert mentioned possible “voltage irregularities, which may need to be corrected, increased drag on low Earth orbit satellites, and intermittent disruptions to satellite navigation systems and high frequency radio.” Those lucky enough to be within the 30-minute predicted auroral extent—essentially, where scientists think the aurora will be visible—can try to view the spectacle if nighttime weather conditions permit.

The strongest geomagnetic storm ever recorded took place in September 1859, when G5-level solar flares produced northern lights that were visible from Mexico to Hawaii. Reportedly, these lights were so bright that miners in Colorado mistook them for the rising sun, and New Englanders were able to read after dusk.

The northern lights we’ll be seeing this week won’t be nearly as bright, but they’ll still be worth a look – especially if you can’t make it to the Arctic any time soon.

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