Several optical phenomena were seen around Flagstaff on June 23, 2016.
Circumhorizontal arcs and sun dogs! And lots of aluminium?
David Blanchard via Facebook
Circumhorizontal arcs, also known as fire rainbows are formed under very strict circumstances:
- The sun must be high in the sky.
- Cirrus clouds have to be present.
- The clouds must be made up of hexagonal ice crystals.
All these particular conditions will make possible to create the colorful rainbow hues among the clouds.
Sun dogs are another kind of atmospheric phenomena. However, they mainly occur horizontally with red often appearing on top while the sun is low in the sky.
Also sometimes called parhelia, they can often create the illusion of multiple suns.