Beautiful! Nature's artwork. I've never seen one of these. Thanks for sharing it with us ;o)

You might want to alert OZ and see if he wants to add the photo to his thread of atmospheric optics and other phenomenon.

Spectacular, isn't it!?!?!!??!

Although not common, I live on the Lake Erie coast and have had the pleasure of seeing this phenomenon a few times as the cold fronts move down from Canada across a very shallow and very warm Lake Erie. This is perhaps the best photo I have ever seen of this. Although, witnessing it in person is much more majestic as the cloud simply vanishes from horizon to horizon. At times this phenomenon is accompanies by water spouts out on the lake - Now THAT is truly a sight to see!!!

Thanks for sharing the pic!
Nature is truly amazing!

NIceee!! I actually have a roll cloud on my phone video as well from last Aug09. Ill try to upload them for you guys but yes this one i got on video was dark and did stretched from one end all the way to the other.

What? What is this?
No one sees a Russian Missle?
Whew! Me neether.

You almost always see the most beautiful skies right after stormy weather OR right before a Cold/Heat wave..

About 3 years ago it had rained for 3 straight days(I live in Tampa FL) and it was finally clearing up.. The sun was starting to go down and the sky was PURE Orange with Pillowy clouds, almost like pillows in the sky.. It's times like that in which I had carried a camera on me at all times...

Amazing is that this is the first cloud related thread where the OP explains the phenomena as it is, a naturally ocurring cloud, rather than blaming aliens or HAARP etc.

The picture really does show the wonder of nature. I too have seen these cloud waves here in the thumb of Michigan usually just before a storm on a hot day. They are most often coming in from the east - off the lake. I just sit and enjoy the beauty of nature.

I've never seen anything like that.
Pretty cool.