JACKSON, Wyo. — The National Weather Service issued a geomagnetic storm watch on Sunday, Jan. 21, indicating that a G2 geomagnetic storm could result in a glimpse of the Northern Lights on Monday, Jan. 22.
A coronal mass ejection (CME) was detected by the service on Saturday, Jan. 20. The resulting plasma interacts with upper levels of the earth’s atmosphere, generating the aurora.
The Kp index is expected to reach level six overnight between Jan. 22 and 23, bouncing between levels three, four and five intermittently. Derived from the German “Planetarische Kennziffer,” or planetary index, the Kp scale runs from zero to nine.
As explained by Wyoming Stargazing, the Kp index “measures the disruption of the horizontal distribution of the geomagnetic activity…A value of zero means that even Fairbanks, Alaska would have difficulty in seeing the northern lights. One to three is most common, and that’s what is frequently seen in those northern latitudes of northern Canada and Alaska. A four would push them down into southern Canada, while a five, 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 six.”
A prediction by the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center forecasts the aurora’s “view line” as passing through the Cowboy State, bisecting it horizontally.
Jackson might be right on the cusp of visibility. Tonight’s forecast suggests cloudy skies in the area, with a 91% full moon. Conditions might not be ideal for aurora views, unfortunately.
Buckrail readers captured beautiful photos of the Northern Lights over Jackson last September. Learn more about the mythologies associated with them here.
