The northern lights are expected to light up Minnesota's sky early this week. Here's the latest forecast.

MINNEAPOLIS — Minnesotans, consider this your aurora borealis alert. The northern lights are likely to light up the sky early this week, but there's still uncertainty in the forecast.

A geomagnetic storm watch is in effect through Wednesday due to several coronal mass ejections, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center. While the CMEs could reach Earth as early as Monday, the brunt of the activity is expected on Tuesday.

When CMEs arrive at Earth, a geomagnetic storm — accompanied by northern lights — can result.

When's the best chance to see the northern lights?

According to data from NOAA , there's a moderate chance to see the northern lights Monday night, with the best chance between 1 a.m. and sunrise on Tuesday.

A waning crescent moon, rising after midnight, will aid in keeping skies dark, but atmospheric haze from humid air will slightly increase the glow from city lights.

There's a minor chance to see northern lights, at least according to the latest forecast, on Tuesday after sunset and before sunrise on Wednesday.

There will be a mixture of clouds and clear skies during these timeframes. While conditions won't be perfect, they will provide at least some time to see the unobstructed sky.

Where are the best areas to view the northern lights?

At this point, the potential viewing area makes up many of the northern states, including Minnesota, as well as some of the lower Midwest to Oregon. But light pollution can make it tough for many to see.

For an optimal viewing experience, move far from higher-populated areas and have a clear view to the north.

The very best viewing would be in the Boundary Waters Canoe Area Wilderness, officially recognized as the closest International Dark Sky Sanctuary.

Acknowledging the difficulty in forecasting northern lights

Simply put, space-weather forecasting is hard. Meaning, there's still uncertainty in the forecast.

The sun is 91 million miles from Earth, which means a fast solar wind reaches us in about 80 to 90 hours; that's why accurate aurora forecasts are hard to make beyond two to three days.

It also means that, if the forecasted solar wind speed is off by only 1% to 2%, the time of arrival at Earth will be 1 to 2 hours different. That's a big impact for such a slim margin of error.

Learn more about forecasting atmospheric weather here .

What causes northern lights?

According to NASA , auroras are caused by waves of charged particles emitted by the sun, known as solar wind.

When those charged particles come into contact with atoms and molecules in Earth's upper atmosphere, they create neon-green waves — similar to the collision of electrons and neon gas in neon lighting.

In May, the northern lights were seen in many areas of Minnesota amid the strongest geomagnetic storm to impact Earth since October 2003.

Besides producing jaw-dropping aurora borealis, solar flares from this storm impacted some power grids and GPS and communications satellites . The storm also disrupted some navigational systems in farming equipment in the Midwest and other parts of the country amid the planting season's peak.