A large coronal hole in the sun’s atmosphere is currently facing Earth, sending a blast of high-speed solar wind our way that could trigger geomagnetic storms and auroras this weekend. The fast solar wind stream is predicted to arrive late Saturday into Sunday (Oct. 11-12), according to space weather forecasters from both NOAA’s Space Weather Prediction Center and the U.K. Met Office.
Geomagnetic activity could start picking up late Oct. 11, with the highest activity slated for between 5 a.m. and 5 p.m. EDT (0900-1700 GMT) on Oct. 12. If minor (G1) geomagnetic storm conditions are reached, auroras could be visible as far south as northern Michigan and Maine.
This isn’t the first time we’ve seen this particular coronal hole, but it looks a little different from last month’s butterfly-shaped feature. Coronal holes can persist for months and reappear every 27 days or so as the sun completes one solar rotation.
When the solar wind reaches Earth, it interacts with our planet’s magnetic field, releasing energy as light that creates the glowing curtains of auroras. This weekend’s timing is good for aurora chasers, as the autumn equinox brings a seasonal ‘bump’ in activity due to the Russell-McPherron effect.
A peak Kp index of 5 is predicted, corresponding to minor (G1) geomagnetic storm conditions. The Kp index measures geomagnetic activity from 0 (quiet) to 9 (extreme). This weekend’s space weather forecast suggests a high chance of seeing auroras farther from their usual polar regions.
For more information on this weekend’s and next week’s space weather, check out the latest forecast from space weather physicist Tamitha Skov.
Source: https://www.space.com/stargazing/auroras/colossal-hole-in-the-sun-could-spark-impressive-auroras-this-weekend-oct-11-12-2025