A coronal mass ejection (CME) released by the Sun on Sept. 28 could reach Earth late Thursday, Oct. 1, and trigger the northern lights across parts of the United States into Friday, Oct. 2. Alaska and 11 states near the Canadian border have the best chances, although forecasters say Friday may offer a better opportunity than Thursday night.

The possible display is not guaranteed. The CME is expected to brush past Earth rather than hit it directly, which could limit the strength of the geomagnetic storm. People in the Lower 48 may see only a faint glow near the northern horizon, depending on how the solar material interacts with Earth's magnetic field.

The possible viewing window runs from Thursday evening into early Friday. A NASA model estimated that the CME could arrive between 8:05 p.m. and 11:15 p.m. Eastern time on Oct. 1, although the timing could shift by several hours.

The National Oceanic and Atmospheric Administration (NOAA) forecast mostly quiet geomagnetic conditions through Thursday, with a better chance of activity on Friday. Forecast estimates put the chance of a minor G1 geomagnetic storm at about 30%, while the chance of a stronger G2 storm is around 10%.

The chances are generally better in places closer to the Canadian border, where the aurora may appear as a faint glow low in the northern sky. Alaska has a stronger chance of seeing the display.

If the storm reaches G2 level, the aurora could become visible farther south, potentially reaching Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Colorado, Pennsylvania, and New York. However, that scenario is less likely based on the current forecast.

For people hoping to see the aurora, the hours between 10 p.m. and 2 a.m. local time are generally worth watching. However, the forecast suggests Friday could bring stronger geomagnetic activity across the Lower 48.

If the activity continues into Friday night, another viewing opportunity may be possible. The timing remains uncertain because the CME's arrival could shift, and the aurora depends on how the solar material interacts with Earth's magnetic field.

Find a dark location away from streetlights and buildings, and look toward the northern horizon. Clear skies are important, as clouds can block the display even when geomagnetic activity is strong.

Give your eyes about 15 to 20 minutes to adjust to the darkness. A smartphone camera with night mode or a long-exposure setting may also capture faint colors that are difficult to see with the naked eye. Using a tripod can help keep the camera steady.

The Moon will be about 73% illuminated, which could make faint auroras harder to see. Checking the latest aurora forecast and local cloud conditions before heading out can help viewers decide whether it is worth looking.

The forecast points to a possible aurora, not a guaranteed light show. People in the northern states have the best chance of seeing it, while a stronger-than-expected storm could push the display farther south.