A cold front moved through Sunday. Before it passed, it brought some high clouds. I noticed them as I was driving home from running an errand. Most were cirrus uncinus, or mare’s tail clouds. Later, near sunset, when I took the dogs out, they were tinted pink by the setting sun. They looked like a painter had dabbed pale pink in the sky, and then whipped the brush up and away. I immediately dragged the dogs back inside to get my phone. By the time I got back outside, just a matter of seconds, the clouds had changed. They were still nice, though.

If you look carefully there is a hint of a bright spot and a little color in one of the clouds. It’s in the left third of the picture, about two thirds of the way from the top. Here’s a closer look.

I’m not quite sure what caused this effect. It was too far from the sun to be a parhelion, or sun dog, but it was about at the same elevation as the sun, which was out of sight behind the mountain. The cloud seems to be too far from the sun to be iridescent clouds, and the colors don’t like quite right to me. I thought it might be part of a parhelic arc, which circles the horizon at the same elevation as parhelia, but those are generally white, without color. If it were part of a parhelic arc, you might have expected to see other parts of it in the clouds, since some seem to be at the right elevation. But maybe not. I’m not aware of any other arc or halo that would appear where it did, so, in the absence of better information, I’ll just assume it’s part of a parhelic arc.