Northern lights could return to the northern horizon of parts of the U.S. and Canada overnight on Saturday, Oct. 3, and Sunday, Oct. 4, with a fast solar wind forecast to trigger G1-class geomagnetic storm conditions.

If aurora reaches the northern U.S., a smartphone camera may detect faint colors that are difficult to see with the naked eye — most likely low on the northern horizon.

Northern Lights Forecast For Saturday, Oct. 3

According to NOAA , there’s “a chance for an isolated period of G1 (Minor) storming late on 03 Oct, following the anticipated onset of a positive polarity CH HSS." That refers to a stream of fast-moving solar wind flowing from open magnetic field regions on the sun. "Periods of G1 (Minor) storming are then likely on 04 Oct as the CH settles into a geoeffective position,” said NOAA.

According to the UK Met Office , “The next significant enhancement is likely to be from a large coronal hole feature. Onset is considered most likely late on day 1 (03 Oct), but there is a chance the arrival of the solar wind enhancement be delayed until day 2 (04 Oct)."

Where Will The Northern Lights Be Visible In The U.S. And Canada?

Conditions are good for aurora watching this weekend. The moon reaches last quarter and rises around midnight, creating a useful dark-sky window during the first part of NOAA’s predicted G1 period.

If G1 conditions do develop, Alaska and states across the northern tier of the contiguous U.S. (Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, Maine, Vermont and New Hampshire) could have opportunities to see or photograph aurora, particularly from dark locations near the Canadian border.

Cosmik has live aurora odds for all U.S. states and 552 cities, updated from NOAA’s data, so you can check whether your location may see aurora.

How To See The Northern Lights In The U.S. And Canada

A G1 forecast does not guarantee the northern lights will appear from any particular location, and apps such as Aurora Now, My Aurora Forecast or Glendale Aurora should be used for up-to-the-minute alerts and live solar wind data. The orientation of the interplanetary magnetic field — measured as Bz — will matter once the CME reaches Earth. A sustained southward Bz can favor stronger coupling between the solar wind and Earth’s magnetic field, increasing the potential for auroral activity to be seen farther south than expected. If Bz remains northward, however, the resulting display may be weak or restricted to higher latitudes.

Skywatchers hoping to witness aurora should head to a dark location with unobstructed views of the northern horizon. In addition to the orientation of the interplanetary magnetic field, aurora visibility will ultimately depend on solar wind strength, cloud cover and light pollution.

Wishing you clear skies and wide eyes.