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The aurora’s are back! And may be visible throughout the weekend. The University of Alaska and NOAA track auroras using the Kp-index, a global auroral activity indicator which has a scale from 0 to 9. It measures the fluctuations in the Earth’s magnetic field, tied to specific geographic locations.

Several states in the northern U.S. are forecast to have the finest views by the National Oceanic and Atmosphere Administration. If the weather is clear this weekend, many northern states should be able to see the northern lights – North Dakota, South Dakota, Iowa, Michigan, New York, Vermont, New Hampshire, Maine, Washington, Idaho, and Montana are among them, according to the Space Weather Prediction Center.

States that may see auroras over the weekend

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The Kp index, which measures activity in Earth’s magnetic field, is expected to peak during the weekend at 4.67, according to the NOAA’s Space Weather Prediction Center. View NOAA’s 3-day forecast for the most recent timing breakdown.

NOAA’s aurora forecast

Earth’s magnetic field acts as a barrier

We’re protected from the solar winds by the invisible barrier that the Earth’s magnetic field creates. Stronger solar winds have the ability to disturb the magnetic field and gorgeous auroras are produced when the planet’s magnetic field’s gasses contact with the storm’s particle stream.

Though uncommon, the display can be visible over Europe and the United States during primarily large auroral events. According to the University of Alaska, during a major event in 1958, the aurora could be seen from Mexico City.

SOURCE NASA, NOAA, Space Weather Prediction Center, Space.com and USA TODAY research