Northern lights could return to parts of the U.S. and Canada late Thursday, Oct. 1, and early Friday, Oct. 2, as a solar eruption heads toward Earth and may trigger minor geomagnetic storm conditions.

Space weather forecasters are monitoring a coronal mass ejection that left the sun on Monday, Sept. 28. The CME — a cloud of magnetic fields and charged particles from the sun — is expected to deliver a glancing blow rather than a direct hit, but it could still produce enough geomagnetic activity to cause displays of aurora across northern parts of North America on Oct. 1-2.

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

The promising forecast comes a few days after a full Harvest Moon and as Saturn comes to its bright annual opposition . A waning gibbous moon will add some natural light to the sky, although conditions will vary by location.

Solar scientists also detected the first solar flare for many weeks on the sun on Sept. 30, which suggests there could now be a period of heightened solar activity — and possible northern lights this weekend.

Northern Lights Forecast For Thursday Night And Friday, Oct. 1-2

The key period for aurora watchers in North America is expected to begin Thursday evening and continue into Friday morning, depending on the CME’s exact arrival time.

“Active to G1 (Minor) storm levels are likely on 02 Oct due to influences from the 28 Sep CME,” said NOAA . According to the UK Met Office, there’s “a chance of G1/Minor storm and a slight chance of G2/Moderate storm intervals on Days 2-3 (01-02 Oct), should we see glancing influence from the 28 Sep CME.”

The exact timing remains uncertain, meaning anyone hoping to see the northern lights should watch for updated forecasts as the CME gets closer to Earth.

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

If G1 conditions 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.

If activity reaches G2, viewing opportunities could extend farther south across parts of the northern and central U.S. (Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Colorado, Pennsylvania and New York).

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.

Northern Lights Forecast For This Weekend: Expect More Aurora

Another source of enhanced geomagnetic activity may also be waiting behind the CME. A large coronal hole is currently sending high-speed solar wind into space. The Met Office says modeling suggests Earth could connect with those faster winds around Oct. 3, which could potentially extend the period of enhanced aurora activity into the weekend.

Early on Sept. 30, the first significant solar flare in weeks erupted on the sun, according to SpaceWeather.com , which could mean enhanced geomagnetic activity this weekend.

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.

Why September Is A Good Time For Northern Lights

Auroras are driven by the natural rhythms of the sun and its complex interaction with Earth’s magnetic field. One factor that can enhance auroral activity around this time of year is the Russell-McPherron effect, first described by UCLA scientists in 1972. It helps explain why geomagnetic activity — and therefore auroras — tends to increase around the equinoxes in March and September.

Around the equinoxes, the geometry of Earth’s magnetic field relative to the magnetic field carried by the solar wind can become particularly favorable for this process. This allows energy and charged particles from the solar wind to enter Earth’s magnetosphere more efficiently.

Those particles can ultimately be funneled along Earth’s magnetic field toward the polar regions, where they help produce displays of the northern and southern lights. The seasonal enhancement in geomagnetic activity extends beyond the exact date of the equinox, making late September and early October a particularly favorable period for auroral activity.

Why You Should Travel North To See The Aurora

If you really want to see the northern lights, don’t wait for them to come to you — go north. The auroral oval typically sits around 65 degrees north latitude, crossing northern Norway, Sweden and Finland, as well as Iceland, Alaska and northern Canada. Travel beneath it and you’ll not only have far more frequent opportunities to see aurora, but a much better chance of experiencing it directly overhead. That’s where the real “wow” factor happens: curtains of green twisting across the sky and, during stronger displays, the spectacular auroral corona appearing directly above your head.

It’s a very different experience from seeing a distant glow low on the northern horizon from the contiguous U.S. or much of Europe. If seeing the northern lights is on your bucket list, chasing them north is a far better strategy than waiting for the next big geomagnetic storm to bring them south.

Wishing you clear skies and wide eyes.