Northern Lights Forecasted Across 15 U.S. States Tonight

A fast-moving stream of solar wind is expected to interact with Earth's magnetic field tonight, potentially causing auroras visible across 15 U.S. states, according to the National Oceanic and Atmospheric Administration (NOAA).

The NOAA's Space Weather Prediction Center (SWPC) forecasts minor (G1) geomagnetic storm conditions, with the Kp index anticipated to reach 5. The Kp index measures geomagnetic activity on a scale from 0 to 9, with higher values indicating stronger auroral activity.

The best viewing opportunities are projected between 11 p.m. and 5 a.m. EDT (0300 to 0900 UTC on August 19).

The 15 states where auroras may be visible include Alaska, Montana, North Dakota, Minnesota, Wisconsin, Michigan, Maine, South Dakota, Vermont, New Hampshire, Idaho, Washington, New York, Wyoming, and Iowa.

This auroral activity is attributed to a large coronal hole currently facing Earth, emitting a high-speed stream of solar wind. Coronal holes are regions in the sun's magnetic field that allow solar wind to escape more readily.

The U.K. Met Office also notes the possibility of minor geomagnetic enhancements continuing into Tuesday and Wednesday due to a potential glancing blow from a coronal mass ejection (CME), though forecasts remain low confidence at this time.

For optimal viewing, individuals in the affected states are advised to seek dark locations away from city lights, with a clear view to the north, and to monitor local weather conditions for cloud cover.