About 3 years ago, I moved to rural western Washington with mostly dark skies; from my backyard, I can see stars down to about 5.5 to 6 mag. I also have several dark sights in the mountains that are only about 15-20 minutes away ...ain't ya envious? LOL.
In the October 1993 S&T, there are plans for making a detector that measures conditions that are favorable for a display.
Oftentimes the cable tv channels have a lot of inerference during solar activity.
Since moving, I've seen the northern lights 10-15 times. Usually they are a subtle, pale, yellowish, white, and would be overwhelmed by any light pollution or moon light. Comparing their visibility to the milky-way would usually be acurate. A few discriptions I've seen are:
1. They Sometimes look similar to shimmering high clouds illuminated by moon-light, and can also be anywhere in the sky.
2. They can resemble sky glow similar to the zodiac lights or light pollution from a distant city. About a year ago, there were several nights of this type of display. I didn't realize what it was until the next night.
3. The oddest display I've seen was one that resembled a jumbo jet contrail on steroids. It was in a mostly straight line, and was about 5X larger than a jet's vapor trail. At first I wondered if it was caused by a small astroid going through the atmosphere.
4. From an airplane; several years ago I spent several weeks in Germany. While flying over Greenland, they produced a nice display. BTW in the daylight, Greenland is spectacular...the glaciers make it resemble a moon-scape.