Northern lights could be visible across the US again tonight. See where.

Nearly two dozen states could catch a glimpse of the northern lights on Nov. 12 after the aurora borealis illuminated skies across the northern contiguous U.S. the night before.

A coronal mass ejection, or large expulsions of plasma and magnetic field from the sun, is expected to reach earth around mid-day on Nov. 12, likely causing increased geomagnetic activity, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center.

On the K-index scale — which indicates how far away from the poles the northern lights could be visible — NOAA is predicting a 6 out of 9 for Nov. 12. A Kp score around 6-7 indicates a bright and active aurora, per NOAA.

On another geomagnetic storm scale, NOAA ranks the event a G2, which is considered a moderate event.

The northern lights, a natural phenomenon formally known as the aurora borealis, can project colorful lights in the night sky because of an interaction between the sun's plasma and Earth's magnetic field, according to the National Weather Service.

Northern lights surprised states not included in NOAA's initial forecast

While NOAA's website anticipates views in only some northern U.S. states, the forecast is only a prediction. On Nov. 11, sky gazers reported seeing the auroras in Texas, Florida, Colorado, and more areas beyond the forecasted view line for that night.

"The aurora does not need to be directly overhead but can be observed from as much as 1000 km away when the aurora is bright and if conditions are right," NOAA's website says. 

"These types of storms can be very variable. There's a lot of dynamics that go on with them," said Shawn Dahl, a forecaster for NOAA, in a video shared on X.

When could the northern lights be visible tonight?

The aurora is not visible during daylight hours and is usually seen just after sunset or just before sunrise. The best view of the northern lights is generally within an hour or two of midnight, according to NOAA.

Where could the northern lights be visible tonight?

Parts of about 18 states are partially or fully within NOAA's forecasted "view line" for the northern lights on Nov. 12. The view line indicates the southernmost point where the aurora could be seen on the northern horizon.

The following states could catch a glimpse of the aurora, according to NOAA's forecasted view line:

• Alaska
• Idaho
• Illinois
• Iowa
• Maine
• Michigan
• Minnesota
• Montana
• Nebraska
• New Hampshire
• New York
• North Dakota
• Oregon
• South Dakota
• Vermont
• Wyoming
• Washington
• Wisconsin

This story has been updated with new information.

Melina Khan is a national trending reporter for USA TODAY. She can be reached at [email protected].