Coronal hole faces Earth

Friday, 17 August 2018 18:56 UTC

The previous coronal hole caused several periods where a Kp of 4 was reached which stands for active geomagnetic conditions. The minor G1 geomagnetic storm threshold was not reached which was to be expected.

Today's coronal hole is located on the Sun's southern hemisphere but is a bit fragmented with the darkest patches near the equator. This coronal hole faced us last month as well and briefly caused active geomagnetic conditions. The NOAA SWPC issued a minor G1 geomagnetic storm watch for this coronal hole last month and considering that the coronal hole opened up a bit over the past few weeks we expect that NOAA issues another minor G1 geomagnetic storm watch. We think that active geomagnetic conditions (Kp4) are likely when the solar wind stream from this coronal hole arrives and yes, even minor G1 geomagnetic storm conditions (Kp5) are not impossible. We expect the solar wind stream to arrive during the second half of 20 August or early on 21 August.