Coronal hole faces Earth, G2 watch issued

Sunday, 31 July 2016 11:52 UTC

The solar wind stream is expected to arrive during the second half of 2 August and this prompted the NOAA SWPC to issue a moderate G2 geomagnetic storm watch. They expect that a small coronal mass ejection from a filament eruption back on 28 July could arrive as well around this time but we expect little to no impact from that event. Nonetheless, this is a trans-equatorial coronal hole and that means we will get hit head-on by its solar wind stream. Solar wind speeds up to 750km/s are possible based on STEREO A data. Enhanced IMF values are expected when the leading edge of the coronal hole solar wind stream arrives and if the north-south direction of the IMF (Bz) dips southward we must conclude that a warning for moderate G2 geomagnetic storm conditions on the latter half of 2 August perhaps into 3 August is justified. If we reach the moderate G2 geomagnetic storm threshold, sky watchers at latitudes as low as the northernmost parts of Germany and northern England as well as the northern United States should be alert for possible auroral displays.

A coronal hole is facing Earth. Enhanced solar wind could arrive in ~3 days - Follow live on https://t.co/T1Jkf6i4Cb pic.twitter.com/si8RT1uOV3

— SpaceWeatherLive (@_SpaceWeather_) 31 juli 2016