The clarity and strength of the Northern Lights vary tremendously, from a faint undulating tinge on the horizon to the fullblown drapery that seemingly hangs about 100 feet above one and everything in between. (They say that the nearest ones are about 40 miles up.) In southeast Alaska the most common phenomenon is the diaphanous pale green curtain. There are frequently two parts to it- one half will kind of march behind the other and shimmer back again.

Two things that many people don't anticipate:

They are in constant motion.
You can see the stars right through them.

Even though Juneau on occasion has stunning visuals, if I were trying to make sure I saw them in a limited period of time I'd travel to Fairbanks and that area. Their skies are much clearer than ours.

They say that Autumn and Spring are the best seasons. And of course, as mentioned above the strongest viewing seasons peak about every 11 years.

Incidentally, I have never heard them - maybe someday - but the native peoples all say that they do sound. They also believe that whistling draws a response. Historically, mind, the natives had a different feeling about them than we do- many cultures tried to chase them away.