JACKSON, Wyo. — Heads up, skywatchers! The northern lights are expected to appear over Canada and the northern U.S. tonight, and Jackson might be right on the cusp for visibility.
According to the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center, a moderate (G2) geomagnetic storm is anticipated to arrive sometime over the next day or so due to an observed solar flare and coronal mass ejections (large clouds of plasma and magnetic fields emitted by the sun).
The Kp index has the potential to reach level 6 between the hours of 11 p.m. and 2 a.m. (Mountain Time), which might make the northern lights visible as far south as the northern half of Wyoming. Derived from the German “Planetarische Kennziffer,” or planetary index, the Kp scale runs from 0 to 9.
As explained by Wyoming Stargazing, the Kp index “measures the disruption of the horizontal distribution of the geomagnetic activity… A 4 would push them down into southern Canada, while a 5, in the right conditions, might just barely be visible on the northern horizon here in Jackson Hole. To see them well, we typically need at least a 6.”
The National Weather Service forecasts mostly clear skies over Jackson tonight, and tonight’s new moon will be nice and dark. To view the aurora on a clear night, head to a very dark place away from light pollution, and allow the eyes to adjust, which could take 15 to 30 minutes. Turn to the north-northeast and look at the horizon. Good luck out there!
