11:06 pm, 5/27
Photos and narrative by Pat Hanrahan: the light dome off to the north before it expanded.
12:28 am, 5/28
The awakening: I was about to quit for the night and had already packed my camera away. But then Greg Babcock notified me that things had suddenly changed.
12:30 am, 5/28
Rays: at this point the aurora was quite active and the rays could easily be seen moving across the sky. Before some of the rays appeared, we could see a bright spot on the horizon that soon shot up into the sky.
12:32 am, 5/28
Brightest point. This unexpected auroral event was caused by the relatively minor Coronal Mass Ejection of May 23. When it arrived, it caused a geomagnetic storm that reached a rating of G3 (strong). TheWeatherNetwork.com ranked the event as "The brightest and most intense auroras since 2015 were spotted over parts of Canada."
Astronomy Community for the Portland Metro Area.