Northern lights display expected to shine bright this weekend in Minnesota

The National Oceanic and Atmospheric Administration (NOAA) has issued a severe (G4) geomagnetic storm warning for May 11 (starting tonight). According to NOAA, a warning for a storm of this severity hasn’t happened since 2005.

Because of the weather conditions, a powerful aurora is expected this Friday night, May 10, into Saturday evening, May 11. However, nothing is guaranteed, even when the conditions seem right. The best time is 10 p.m. to 4 a.m., according to NOAA.

Northern lights occur when charged particles are launched into space, and a Coronal Mass Ejection (CME) happens during a solar flare. The particles travel through space and hit the planet’s magnetic field. Some get trapped by the magnetic field. The electrons, protons, and ions from the sun collide with nitrogen and oxygen, creating a brilliant display. Oxygen creates green, and nitrogen creates purple, blue, and pink.

How are solar flares measured?

Solar flares are divided into classes. There are A, B, C, M, and X class flares. The most powerful is an X-Class, and the M-Class is the most common when people see the northern lights. Each class has 10 numbers: M1, M3.5, M7, etc. Anything below an M-Class flare doesn’t usually produce anything visually.

When a solar flare occurs, it doesn’t mean it will produce the northern lights. It needs a CME to make it across space to our planet. And even when a solar flare occurs with a CME, it doesn’t mean you’ll see them, either.

You also need the solar winds to be right to see them. Solar winds are the rate of speed at which particles travel through space. You usually need them to be 218 to 310 miles per second or more to have them be visible.

Another thing that needs to line up is the Bz index, which means the direction of the solar wind’s magnetic field when it reaches Earth. For this, you want the numbers to be negative.

Additional information

When you look up apps that show the northern lights, they are in the UTC (Coordinated Universal Time) time zone. To know the UTC time for the Central Standard Time of Minnesota, we’re five hours behind the UTC time zone.

You will also see a lot of the KP Index, which measures geomagnetic activity. Generally, if you’re in northern Minnesota, a KP of 4 or sometimes 3 in the right conditions can create visible northern lights. To see them in the Twin Cities, you’ll want a KP of 5 or more.

How to see the northern lights

This is a lot of information to take in. But to see northern lights, you don’t need to know all of this. If you want to see them, just wait until it’s a high enough KP, try to get away from the light pollution of the Twin Cities (driving north is your best bet), and look north without anything obstructing your view. Lakes work great for viewing them. Light pollution has a big impact on seeing them. If the moon is big, it can make it so you won’t see them either. So wait until it’s a quarter moon or less, or it sets before midnight.

Other things to consider

Northern lights never look like they do in photos because camera sensors work differently than our eyes. But if the show is powerful enough, you can see them with the naked eye.

Look for what seems like light pollution. It’s a very faint green glow most of the time. Expect to fail the first few times. But eventually, you’ll learn how to see them. And be happy that we’re located where we are. Minnesota is the best state in the Lower 48 states for seeing them. You’ve probably seen them before and didn’t notice what it was.

If you plan on going out, good luck! Make sure to pack bug spray, some snacks/beverages, and warm clothes. If you plan to travel north for it, I recommend being north of the Twin Cities. Avoid being directly south of Duluth; light pollution makes a difference. Or, if you want to make a day trip, go north of Duluth. Please note that any stores north of Two Harbors, MN, close after around 10 p.m., so make your stops before then.