Silver Clouds

When I was walking by the harbor yesterday I noticed that there were very complex cloud layers in the sky.  It was quite beautiful, looking at the silvery tones and the different patterns.  What attracted my attention were the streaks running from the center of the photo up and to the left.  The streaks at first looked like contrails from jet exhaust, but they were at too low an altitude.  So I have no idea what was going on, unless these clouds were the result of some frontal activity moving through.  In any case, I love how beautiful this scene was.