I saw this on my trip to my grandmother's a couple of weeks ago and wondered if it was anything. So I wrote to the Astronomy Picture of the Day and heard that it was something!

I'm listed under the August 2012 section with pictures from Milbridge on July 24. http://asterisk.apod.com/viewtopic.php?f=29&t=29213#p180840

What's really neat is that there are three different things happening in the #2 picture, which is pictured above: Cloud shadows, sun rays and Kelvin-Helmholtz Waves. I love the Waves! (The link to see other shots of that is here, then find it in mine if you can: http://cloudappreciationsociety.org/collecting/giselle-goloy/)