The Night
A CME impact occurred during the morning hours (central time) of October 10. This CME brought Bz dropping as low as -20 nT and a total magnetic field strength (Bt) up to 40 nT during what is known as the shock phase. This timing of the impact was best for Europe, and auroras were visible at least as far south as Luxembourg. However, these conditions only lasted a few hours, and when we got into the interior of the CME, Bz became north between 10 and 15 nT. In a lot of cases, this brings an end to the auroras, and that's what I somewhat expected tonight.
Sometimes, you can see a residual glow from the initial impacts of the time period when Bz was south, and when the solar wind is still fast and compressing Earth's magnetosphere, it is possible to see a bit of a glow in the northern sky even when Bz is not favorable. Tonight was a different story. The auroras behaved as if Bz was SOUTH about -5 or -7 nT and steady.
I had been at a wedding
