Powerful Solar Storm Lights Up U.S. Skies — Why the Northern Lights Reached So Far South

What happened and why auroras spread

A strong burst of solar energy — driven by coronal mass ejections (CMEs) — struck Earth's magnetic environment on Tuesday, Nov. 11, and its effects continued into Wednesday, Nov. 12, according to the National Oceanic and Atmospheric Administration (NOAA).

NOAA's Space Weather Prediction Center issued a rare "severe" geomagnetic storm watch for those dates and rated the event at G3 with the potential to approach G4 intensity on Nov. 12. On NOAA's scale, G3–G4 storms are classified as strong to severe and can cause widespread voltage control problems in ground power systems and disrupt space-based operations.

How the aurora forms

The aurora occurs when electrically charged particles from the sun, carried in CMEs and solar wind, enter Earth's magnetosphere and funnel along magnetic field lines toward the polar regions. There those particles collide with oxygen and nitrogen atoms in the upper atmosphere, exciting them; when the atoms return to their normal state they release photons — visible as the green, red, blue or pink curtains and ribbons known as the northern and southern lights.

Why this storm pushed auroras far from the poles

NOAA reported a Kp index of 6 for this event. The Kp index estimates how far from the poles auroras may be visible: higher values mean the auroral oval expands toward lower latitudes. With Kp=6 and G3-level activity (with the potential for G4), auroras became brighter and visible much farther from the polar regions than during typical conditions.

Where people saw the lights

NOAA initially forecast auroras for about 21 states; observers reported seeing dramatic red, green and other hues as far south as Texas, Florida and Colorado on Nov. 11 — in some areas beyond the predicted view line. For Nov. 12, roughly 18 states remained wholly or partly inside NOAA's forecasted "view line," the southernmost horizon where the aurora could appear.

Risks alongside the spectacle

While the storm produced spectacular night skies, the same geomagnetic energy that creates auroras can also disrupt technology. Strong geomagnetic storms may interfere with satellites, GPS signals, radio communications, and even ground infrastructure such as power grids. Infrastructure operators were notified so they could take protective measures, NOAA said. NASA also warns that extreme solar events can pose risks to spacecraft and astronauts.

Earlier in May 2024, a historic geomagnetic storm prompted reports of power grid irregularities, GPS interference and problems with precision farming equipment. That event led NOAA to issue a rare G4 storm watch — the first in 19 years — and it included the largest solar flare recorded since 2017.

When and how to watch safely

Predicting the exact timing and location of auroras remains challenging; reliable forecasts are usually only possible hours to a few days in advance. As a practical rule, NOAA says the best viewing is often within an hour or two of local midnight if skies are clear. To improve your chances, move away from city lights and light pollution and head to a dark, open location with an unobstructed northern horizon.

NOAA offers real-time tools to help skywatchers, including an aurora dashboard and a 30-minute forecast that provide near-real-time updates on viewing opportunities.

Context — solar cycle and what to expect next

The uptick in activity is linked to the sun's 11-year cycle: solar maximum reached a peak in 2024, and elevated activity is expected to continue into 2025. That increases the likelihood of more frequent "space weather" events capable of producing auroras at lower latitudes. However, timing and exact visibility remain uncertain.

Original reporting by USA TODAY. For real-time alerts and viewing forecasts, consult NOAA's Space Weather Prediction Center and aurora dashboard.