These pictures are automatically updated every 15 minutes. The image on the left shows the size and location of the impact zone of energy particles from the sun. This is displayed as a green circular belt of auroral emissions around the geomagnetic pole, known as the auroral oval. On the image you can read the kp index. This index tells you how much geomagnetic activity there is in the atmosphere. The higher the score, the better chances for seeing the northern lights. In addition you need the weather outside to be clear, meaning no clouds.
The image on the right shows the local all-sky view, with sun, moon and star positions. Here you can read which direction on the sky you can see the northern lights. This is displayed as a green light north, east, south or west.
Can't see the images? For mobile users, this information is also available through a free mobile application called 'Auroral Forecast', available through Windows Market Place, Apple App Store and Google Play.