Cirrostratus with mock sun ~ usually signal the approach of a warm front.
Cirrostratus clouds | UCAR Center for Science Education
a "fire rainbow" - ice-halo formed by plate-shaped ice crystals in high level cirrus clouds
cirrostratus cloud | Cirrostratus Clouds Weather Cirrostratus cloud structures
Check out these incredible photos of Earth's weather from space. They'll blow your mind!
Ring Around the Moon
CIRROSTRATUS Haze This photo, taken near sunset in Colorado by Kevin Larman, show a very thin and very uniform cirrostratus cloud with streaks of thicker cirrus (perhaps old contrails?). Near the horizon some opaque low clouds are visible.