I've only seen auroras thrice in my life, and two of them were above Haninge, just south of Stockholm. This is a bit uncommon - usually you see auroras in the north of Sweden.
Unfortunately, I haven't had the right equipment to take a photo, so I tried making my own picture of one of them.
Some time after I had seen this one, I read that sometimes holes in the magnetosphere can be created spontaneously for a short while, only to disappear as suddenly, and no one know how or why.
I imagine that's what happened the evening I saw the aurora above - it was as if the coloured light was streaming out from a point in the middle.