CIR and Coronal Hole Bring Quick Burst of Aurora to Northern Europe Sept 14, 2017

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Northern Lights Now – The expected G1/G2 storming from the coronal hole pointed towards Earth on Sept 11 arrived late on Sept 13. It induced a period of fast solar wind, strong Bt and G2 storming. The timing was good for our aurora hunting followers in Northern Europe who had clear skies.

Boulder Recorded Planetary K shows two periods of G2 storming in last 15 hours.
Boulder Recorded Planetary K shows two periods of G2 storming in last 15 hours.

At the onset of the storm, Bz was strongly (-15 to -18 nT) south for over half an hour at the beginning of the storm, which set up Earth’s magnetosphere to be highly activated. This means that any additional strong wind, high density, or prolonged negative Bz can quickly jump the KP back into G1/G2 range.

Bz and Bt are strong and favorable at the onset of the storm.
Bz and Bt are strong and favorable at the onset of the storm.

Here are a couple Tweets share with NLN from tonight’s storming

From the Nidderdale in northern Yorks by @HudsonWeather

From Christopher Suarez in Iceland

It is still possible that there could be additional storming. Keep your eyes on the Solar Wind Data. If there is a prolonged people (more than 45 mins or so) of negative Bz, there could be another round of storming.

Note: The current storm is likely the last for a while. There are now active regions that pose M or X class flare threats on the Sun and the next Coronal hole isn’t expected to reach Earth until late September. Make hay while the Sun shines!

Happy Hunting