NASA'S SOLAR DYNAMICS OBSERVATORY SHOWS THE OUTLINES OF THE CORONAL HOLE ON OCT. 24TH

CHANCE OF STORMS THIS WEEK: NOAA forecasters estimate a 35% chance of polar geomagnetic storms on Oct. 25-26 when Earth enters a stream of high-speed solar wind flowing from a coronal hole on the sun. Analysts say storm levels could reach category G2, which means bright auroras are likely around the Arctic Circle. The glow might even be visible from northern-tier US states such as Minnesota and Michigan. Free: Aurora Alerts.

This image from NASA's Solar Dynamics Observatory shows the outlines of the coronal hole on Oct. 24th:

Coronal holes are, essentially, gaps the sun's atmosphere where the magnetic field opens up and allows solar wind to escape. They typically appear once or twice a month. This coronal hole is, however, larger than usual, and the emerging stream of solar wind is broad. Earth could be inside it for 3 days or more. Stay tuned for updates as the solar wind approaches.