M3 solar flare with earth-directed CME

Friday, 19 June 2015 00:45 UTC

Strong M3.06 solar #flare from #sunspot region 12371 - Follow live on http://t.co/XHATH0OOfT pic.twitter.com/Qd6QVGyRUa

— SpaceWeatherLive (@_SpaceWeather_) 18 juni 2015

Video: the M3.0 solar flare as seen by SDO in the 193 Angstrom wavelength.

The solar flare was a long duration event and despite only being a minor event when it comes to strong solar flares, it produced a very respectable coronal mass ejection. As was to be expected, the bulk of the plasma cloud can be seen heading well east of Earth but on SOHO/LASCO C2 (see animation below) we can see that the coronal mass ejection expands to form a full halo around the coronagraph and that means good news for sky watchers around the world: this plasma cloud will likely arrive at Earth.

CACTus estimates that the coronal mass ejection left the Sun at a speed of about 800km/s. Factoring in the current ambient solar wind speed of 400km/s which will slow down the CME a bit, we conclude that the coronal mass ejection will take about two and a half to three days to arrive at Earth. We expect this coronal mass ejection to arrive at Earth around 12:00 UTC on Sunday (June 21) with a plus/minus of 6 hours.

As we said before, the bulk of the coronal mass ejection is not coming towards us but the halo was very well defined on LASCO which means we do expect a decent impact. There will be a good chance for minor G1 geomagnetic storming conditions after the plasma cloud arrives with a lesser chance for moderate G2 geomagnetic storming conditions if the direction of the IMF (Bz) cooperates.