The strongest of several coronal mass ejections produced a powerful geomagnetic storm that illuminated North American skies on Nov. 11, with auroras seen as far south as Florida. The Space Weather Prediction Center recorded G4 (severe) conditions at 8:20 p.m. EST and warned effects could continue into Nov. 12, potentially impacting power, communications and precision GPS. Forecaster Shawn Dahl said the first two CMEs were stronger than expected and a third, even more energetic ejection, was forecast to arrive around midday on Nov. 12. Photos and reports came from at least ten U.S. states.
Spectacular Auroras Dazzle North America During G4 Geomagnetic Storm
The strongest of several coronal mass ejections produced a powerful geomagnetic storm that illuminated North American skies on Nov. 11, with auroras seen as far south as Florida. The Space Weather Prediction Center recorded G4 (severe) conditions at 8:20 p.m. EST and warned effects could continue into Nov. 12, potentially impacting power, communications and precision GPS. Forecaster Shawn Dahl said the first two CMEs were stronger than expected and a third, even more energetic ejection, was forecast to arrive around midday on Nov. 12. Photos and reports came from at least ten U.S. states.
05:35 PM, 11/12/2025Science
Spectacular auroras light up North American skies after powerful solar storm
Vivid curtains of color swept across much of North America on Nov. 11, visible as far south as Florida, after a strong geomagnetic storm reached Earth's atmosphere and ignited widespread auroras.
The Space Weather Prediction Center (SWPC) in Boulder, Colorado, warned that the disturbance — which reached G4 (severe) storm levels at 8:20 p.m. EST on Nov. 11 — could affect the power grid, disrupt communications and degrade some GPS signals into Nov. 12 as the event continued.
Social media feeds quickly filled with dramatic photos after sunset as observers captured the dancing lights across the northern horizon.
What caused the display
Geomagnetic storms occur when a coronal mass ejection (CME) — a burst of solar material and embedded magnetic fields from the sun — arrives in Earth's environment. The SWPC reported CMEs on Nov. 9 and Nov. 10 and a solar flare on Nov. 11; one of those ejections arrived on Nov. 11 and contributed to the stunning auroral activity.
"The first two CMEs were profoundly stronger than we anticipated," said Shawn Dahl, a space weather forecaster at the SWPC. Forecasters expected a third CME to arrive around midday on Nov. 12 and described it as the most energetic of the three.
Potential impacts
Officials cautioned that precision GPS users could see degraded signals. "If you need to be accurate to less than an inch, it could be off by much more than that if this type of activity continues," Dahl said. SWPC staff also notified space launch operators, utility managers and senior White House officials to keep them informed of the evolving situation.
Why the lights show different colors
The visible colors arise when incoming solar particles collide with gases in Earth's upper atmosphere. Interactions with oxygen produce green and red glows, while collisions with nitrogen yield blue and reddish tones, according to the University Corporation for Atmospheric Research (UCAR).
For particularly strong auroral displays, CMEs must carry a magnetic field orientation opposite to Earth's, allowing charged particles to funnel toward the poles and light up the night sky.
Where the auroras were seen
Photographs and reports of the lights were shared from numerous states, including:
- Alabama
- Arkansas
- Florida
- Illinois
- Massachusetts
- Maryland
- Oklahoma
- South Carolina
- Texas
- Minnesota
Observers were encouraged to check SWPC updates for forecasts and potential impacts if planning activities that depend on high-precision navigation or communications.
Reporting: Dinah Voyles Pulver, USA TODAY. Contact: dpulver@usatoday.com.