CORONAL HOLE: A coronal hole has formed in the sun’s northern hemisphere, and it is spewing solar wind into space. NASA’s Solar Dynamics Observatory photographed the UV-dark gap during the early hours of August 14th:
In the image, above, the sun’s magnetic field is traced by white curving lines. The coronal hole is where those magnetic field lines have opened up, allowing solar wind to escape. A stream of solar wind flowing from this coronal hole is expected to reach Earth on August 16-18. NOAA forecasters estimate a 25% chance of polar geomagnetic storms when the windy stream arrives.