Northern Lights Possible Over U.S. This Week As Strong Geomagnetic Storms Predicted, Say Scientists

Have you ever seen the Northern Lights? If you live in northern U.S. states near the Canadian border then the night skies could play host to the sky phenomenon—also called the aurora borealis—at around midnight local time this Monday, Tuesday and Wednesday.

In the wake of the Sun “waking-up” there have been reports of strong displays of aurora in the night sky in recent weeks, but so far they’ve been confined to the Arctic Circle.

However, the latest predictions from the NOAA Space Weather Prediction Center (NOAA SWPC) suggest high activity is coming this week that could mean aurora borealis being visible as far south as Oregon.

Whether anyone sees them depends not only on “space weather,” but also on local weather since heavy cloud will preclude any sightings. The Moon is also waxing towards being a full “Harvest Moon” on Thursday, so that will slightly bleach the night skies, too.

Where and when will the Northern Lights be visible this week? Here’s everything you need to know about the strong possibility (and that’s all it is) of the aurora borealis coming to parts of the U.S. this week.

What is the forecast for the Northern Lights in the U.S. this week?

NOAA SWPC issues a daily forecast, for the next three days, of geomagnetic activity. Its current forecast for September 28-30, 2020 includes a period of strong activity measuring Kp5 and Kp6 (see below for an explanation of the Kp scale), which could means visibility in the northern U.S.

When will the Northern Lights be visible in the U.S. this week?

Those times are in Universal Time, so you need to translate them back into your local time. Do that and you’ll see that around midnight on Monday, Tuesday and Wednesday are the key times to be outside looking to the north.

Look to the south and east and you’ll easily see Mars and Jupiter.

Where will the Northern Lights be visible in the U.S. this week?

The Northern Lights are typically seen between 64º and 70º north in places like Alaska, northern Canada, Norway, Finnish Lapland, Swedish Lapland, northern Russia and Iceland.

However, Kp5 geomagnetic storms are predicted, which means they may be visible as far south as (probably northern areas of) the U.S. states of Montana, North Dakota, Minnesota, Wisconsin and Michigan, as well as southern Ontario and Quebec in Canada.

If they reach Kp6—which is possible—then (northern areas of) Washington, South Dakota and northern Maine may also come into play. Possibly even Oregon.

How to see the Northern Lights this week from the U.S.

Here’s how to approach looking for the Northern Lights this week from northern U.S. states this week:

• Check the weather forecast for a clear sky.
• Make a plan to be somewhere with a clear horizon to the north, preferably one that doesn’t feature a town or city (light pollution will make your search harder). Be there around midnight.
• Preferably choose a dark sky site. Check the Light Pollution Map, Dark Site Finder and Find a Dark Sky Place.
• Let your eyes adjust to darkness for about 20 minutes.
• Keep your expectations in check; you’re most likely to see a layer of green above the northern horizon, and not an all-out geomagnetic storm above your head.

How to photograph the Northern Lights this week from the U.S.

If it’s a particularly subdued display, use a manual camera to find it; put a DSLR on a tripod, point it north, and put in these manual settings:

• Use as wide angle a lens as you have and set the aperture to as low as possible (say, f/2.8 to f/4.5).  
• Shoot in RAW format, not just JPEG.
• Switch the color temperature to tungsten.
• ISO 800 (try up to ISO 6400 if you have a full-frame DSLR).
• Put your lens into manual mode and turn the focus dial to infinity (look for the ∞ symbol). Check the focus every few shots and adjust if necessary.
• Shutter speed: 25 seconds (if you can see movement in the aurora, take that down to 10 seconds).

With those settings dialled-in, it’s time to take a few shots and then experiment.

The next day, use Photoshop or other photo editing software to change the light levels in the RAW images and you’ll likely get great images of the Northern Lights.

What is the Kp index?

The most important number in any geomagnetic forecast is the Kp index. The Northern Lights hang around the north pole in an oval, known as the auroral oval. The Kp index—a scale of 0 to 9—tells you roughly how far south the displays will be visible from.

Kp5 and Kp6—which is what’s being predicted this week—corresponds to G1 (minor geomagnetic storm) and G2 (moderate geomagnetic storm), respectively. That means strong geomagnetic activity whereby a lot of charged particles from the Sun will be accelerated back to Earth from the magnetic field behind the planet.

This map helps show you where you might expect to see displays of various Kp levels.

The NOAA SWPC issues 3-hourly “Kp” forecasts for three days, which suggests how strong the displays may be and how far south it may be visible from.

It’s not an exact science and cloud could easily ruin any displays, but with activity strong in the last week and predicted to get stronger in the coming days, there’s only one way to miss the Northern Lights for sure—and that’s not to make the effort to look.

Wishing you clear skies and wide eyes.