Iridescent lee-wave clouds

There were some wonderfully iridescent lee-wave clouds this afternoon (2 Jan 2009). I found the cloud shapes quite fascinating. The Sun is just off the upper right corner of the image. Edited Jan 7, 2009: improved by cropping and straightening the image.

Very cool. Nice capture

Fantastic color!

Thanks, lostid and HQP. The camera did better than my naked eye on this one, as the clouds were almost overwhelmingly bright. I processed the three RAW images, taken at exposures of +2, 0 and -2 stops, using Photomatix with tone mapping. The final image was sharpened, slightly brightened, and converted to JPG, using Picture Window Pro.

Wonderful, and even the roof is wavy

Harold_L wrote in post #6990017
There were some wonderfully iridescent lee-wave clouds this afternoon (2 Jan 2009). I found the cloud shapes quite fascinating. The Sun is just off the upper right corner of the image.

I see you are in Boulder, I have been seeing these so called "rare" clouds a lot over the past two months here in Denver. They where really intense today

That's just plain cool!

At the top of the thread is my revised version of this image.

Wow, Harold. You are always getting some unusual clouds and/or lighting, but this is really special. Good job with this capture.

Thanks much, Stan. I'm pretty much a convert to HDR and Photomatix now. I don't think I would have done nearly as well without it.

Wow-very unique. I've never seen anything like that! Does anyone know the reason for these clouds?

Nice edit!

Thumbsup wrote in post #7027915
Wow-very unique. I've never seen anything like that! Does anyone know the reason for these clouds?

Sort of like how a rainbow forms. Since clouds are mostly water vapor and ice, this iridescence happens when the ice crystals are about the same size and lined up just right and they reflect light just like rain does. They tend to happen with colder weather, such as fall and winter. They form some times really close to the sun and can be very bright so if you do hunt for them be careful.

A polarizer helps out a lot.

I found this page that has some info too: http://www.atoptics.co​.uk/droplets/irid1.htm

Quoting from the National Audubon Society book, Field Guide to North American Weather:

"Iridescence: Colorful bands or patches observed in clouds seen near the sun or moon.
....the colored bands are due to light being diffracted by water droplets of fairly uniform size in altostratus and altocumulus clouds."

It is pretty common to see iridescence in the lee wave clouds formed when the wind blows over the divide in the rocky mountains, and the moisture condenses out as the air drops and warms up.

Thanks all for the info about the clouds. Again, nice image.