The northern lights could become visible across parts of the northern U.S. overnight Wednesday, Sept. 23, and Thursday, Sept. 24, as a potent stream of solar wind interacts with Earth’s magnetic field.

Space weather forecasters predict up to a G2-class geomagnetic storm, which could bring aurora into view from northern-tier U.S. states near the Canada border. If that happens — and nothing is guaranteed — you can photograph the northern lights with a phone .

The promising forecast comes as the moon waxes towards being a full Harvest Moon on Sept. 26, so strong moonlight in the south may make it harder to see faint aurora in the north.

Northern Lights Alert For Tonight

According to a forecast by space weather experts at the National Oceanic and Atmospheric Administration, a G1-class geomagnetic storm could begin around midnight, with Kp 5.33 conditions forecast.

“Unsettled to active conditions are expected by late on 23 Sep as CH HSS effects begin,” states NOAA, referring to a coronal hole high-speed stream and the coronal mass ejection. “G1 (Minor) geomagnetic storms are likely on 24 Sep, particularly in the early hours, as CH HSS effects continue and strengthen.”

According to a forecast by the UK Met Office, “Active (Kp4) intervals are Likely, with a Chance of G1/Minor Storms (Kp5) or G2/Moderate storms,” overnight on Sept. 23-24.

Northern Lights Forecast For The U.S.

If G1 geomagnetic storm conditions develop, the aurora could become visible from dark locations across northern-tier U.S. states near the Canadian border. Potential viewing areas include Alaska and parts of Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, Maine, Vermont and New Hampshire, provided skies remain clear.

Should geomagnetic activity strengthen to G2 levels — however unlikely — the auroral oval could expand farther south, potentially allowing photographers in states such as Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Colorado, Pennsylvania and New York to capture faint displays.

Aurora-chasing website Cosmik has live odds for all states and 552 cities in 10 languages, updated from NOAA’s data, so you can check whether your location may see aurora tonight.

Aurora Tonight: Best Viewing Conditions

Skywatchers hoping to witness aurora should head to a dark location with unobstructed views of the northern horizon. Aurora visibility will ultimately depend on the strength of the solar wind, cloud cover, light pollution and the orientation of the interplanetary magnetic field. The latter, known as Bz, is critical — when Bz points south, it can connect more efficiently with Earth’s magnetic field, allowing energy and charged particles to enter the magnetosphere.

A sustained period of southward Bz could make the aurora brighter and push it farther south than expected. If Bz remains northward, however, the resulting display may be weak or restricted to higher latitudes. Use apps such as Aurora Now, My Aurora Forecast or Glendale Aurora for up-to-the-minute alerts and live solar wind data.

Wishing you clear skies and wide eyes.