After you review the forecasts, you will have to make a decision about whether or not you will go out to view. Realize that if you live in a city, you will have to drive out of town to dark skies because most displays are too weak to be seen within city limits. However, there are exceptions when the displays get really bright. If you live in a rural area, and have little light pollution to the north, you should be able to easily look out the window to see if there is a display.
Understand that you may or may not see a show a display can range from brief – say 10 minutes – to all night. Also understand that the forecasts are not perfect. There is still a lot to learn about the science of predicting the northern lights.
Check the weather forecasts – specifically the clouds and moon. Obviously, clouds interfere with viewing, but clouds can move out during the night, and weather forecasts aren't always accurate. A good resource to predict cloud cover for the upcoming night is Clear Dark Sky. Also, strong moonlight can interfere with the weaker displays, making it hard to see them.
One of my recommendations to people who want to see the northern lights is to be persistent. View web sites EACH NIGHT. Visiting them on a weekly basis will not work. Also, go out often. I have learned that in order to view the northern lights, I have had to experience a lot of failures, but with the failures comes success.
Also, if you hear that a show was good the night before, don't expect to see a similar show the following night. In most cases, it doesn't happen. The day after a major display, newcomers to discussion forums always ask, “can I see the same display tonight.” Most likely, the answer is no as strong displays typically don’t last longer than one night.
What will you see if you go out? One of the most common sights is a weak glow to the north. This is nothing spectacular to see or photograph, but it could be followed by something better. Often an arc will form in the northern sky, and the arc can sometimes get very bright during substorms. This is often followed by rays forming above the arc. This is when viewing is often at it's best, and when you will want to take photographs.
During stronger shows there can be more color variations, including times when parts of the sky turn red. Stronger shows often feature more movements, and northern lights in other directions, east, west, overhead and south. If such a strong show occurs, it's something that you will never forget.
Often during the morning hours, the northern lights will feature a pulsating action, which is very beautiful to see, but difficult to accurately capture on photographs.
What colors will you see in a display? Green is the most common, followed by green with red shading on the top. During the very large displays, as mentioned previously, large parts of the sky are sometimes all red. Also, when tall auroras are exposed to sunlight (about one hour after sunset and in the hour prior to dawn) or bright moonlight, the northern lights can be blue or purple.
Oh, by the way, when you are viewing the northern lights, you might believe that they are touching the earth, but in reality, the northern lights range anywhere from 60 to 300 miles in the sky.
Next - Photographing the Northern Lights