The Kp index of magnetic activity hit “5″ at 10 p.m. (CDT) and the auroral oval is thick across Canada. Auroras are possible tonight; keep an eye on the northern sky for any telltale green arcs or glows if you live in the northern U.S. and southern Canada. I’ll report back later.
The above is what I wrote just after 10 o’clock. Once twilight faded around 11:15 p.m., the aurora was indeed at work in the northern sky, building arcs and tall, faint rays to an altitude of some 40 degrees. The display continued into the wee hours. At 1 a.m. just north of Duluth, Minn., colorless arcs and patches danced across the north to 25 degrees. They were plainly visible even with the moon up. Enjoy the pix while I enjoy some sleep.
PS. Yes, there’s a continued chance for more auroras Monday night.