Slow earth-bound coronal mass ejection

Monday, 18 July 2016 18:51 UTC

A clear shock arrival should not be expected due to the slow speed (about 300~350 km/s) of this coronal mass ejection. The plasma cloud travels at a similar speed as the background solar wind and this makes it harder to detect but an increase in the strength of the IMF should become noticable when the cloud passes our planet most likely on 22 July. It is hard to say what kind of geomagnetic activity we should expect as its crucial with these kind of events that the IMF (Bz) turns southward but for sky watchers at high latitudes it might pay off to stay alert in the days ahead.

Image: It isn't easy to spot but sharp eyes can see the outline of a faint coronal mass ejection with an earth-directed component on this image from SOHO/LASCO.

A C4.4 solar flare that peaked today at 08:23 UTC was associated with a Type IV radio sweep but it does not look like it launched a coronal mass ejection.