The northern lights could blind millions of Americans in some northern states this weekend. An eruption of solar material from the sun earlier this week could lead to a show of the northern lights if weather conditions are right, officials said.

The eruption, called a coronal mass ejection, prompted the federal government’s Space Weather Prediction Center in Colorado to issue a geomagnetic storm watch for Friday, Saturday and Sunday to warn people of possible disruptions to navigation, power and radio systems.

What time will the Northern Lights be visible tonight?

The Northern Lights can be seen just after sunset and just before sunrise, but the center says it’s best to go outside at night and away from the city lights.

The center recommends viewing the Northern Lights between 10 p.m. and 2 a.m. local time. According to the center, the best times of year to see the Northern Lights are around the spring and autumn equinoxes. The autumnal equinox was on September 22.

Where can you see the Northern Lights tonight?

The center said the northern lights could be seen as far south as Iowa, Oregon and Pennsylvania.

When conditions are right and the Northern Lights are clear, they can be seen up to 1,000 kilometers away, according to the center.

Northern Lights card for tonight

The center has released a map showing the Northern Lights forecast for Friday evening. The map illustrates the predicted intensity of the Northern Lights over North America, with a line showing how far south the lights were seen on the northern horizon.

Northern Lights card for tomorrow evening

The center has also released a map for Saturday evening.

Parts of the country were treated to the Northern Lights last spring when a powerful geomagnetic storm reaches the earth. Although the storm expected this weekend is considered strong, it is not expected to be as powerful as May’s.