The National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center (SWPC) has predicted that the aurora borealis, or northern lights, could be seen across much of the northern United States on Wednesday night (November 12).
Nearly two dozen states may catch a glimpse of the colorful lights after a coronal mass ejection (CME) — a large burst of plasma and magnetic field from the sun — reaches Earth around noon, NOAA said.
A mild geomagnetic storm is expected
NOAA has issued a G2 geomagnetic storm warning, which is classified as a moderate event on its storm scale.
On the K-index scale, which measures geomagnetic activity and auroral visibility, the agency predicts a Kp level of 6 out of 9, indicating a bright and active aurora.
Where to see the Northern Lights
Parts of at least 18 states fall within NOAA’s predicted “line of sight” — the southernmost edge of where the aurora could be visible on the northern horizon.
States included in the projected monitoring zone:
Alaska, Idaho, Illinois, Iowa, Maine, Michigan, Minnesota, Montana, Nebraska, New Hampshire, New York, North Dakota, Oregon, South Dakota, Vermont, Washington, Wisconsin and Wyoming.
Although the line of sight predicts visibility primarily in the northern states, observers in the south may also be in luck. On November 11, auroras were seen in Texas, Florida, and Colorado, outside the expected range of visibility.
Best viewing times
The aurora borealis is usually visible just after sunset or before sunrise, with best visibility one to two hours after midnight, according to NOAA.
Auroras are invisible in daylight and appear as glowing curtains of green or red light centered around the Earth’s magnetic pole.
How the Northern Lights are formed
Auroras occur when electrically charged particles from the Sun collide with Earth’s magnetic field. These charged ions travel in the solar wind and interact with Earth’s ionosphere, about 60-80 miles above the surface, causing the gases to glow — much like neon lights.
This phenomenon varies in intensity and movement, often appearing as shimmering curtains, waves, or streaks of color across the sky.
When Aurora activity peaks
Auroral activity tends to increase during periods of solar maxima – times of increased solar activity – and is more common in the winter months when nights are longer and skies are brighter.
