While on a walk Sunday afternoon, I saw these high altitude Cirrus clouds racing left to right - west to east. They were at least 20,000 + feet up...because the mountain - Lone Peak - next to our neighborhood is 11,253 feet ASL and these clouds were more than twice that.

The Wiki says: Cirrus fibratus or also called Cirrus filosus is a species of cirrus cloud. The name cirrus fibratus is derived from Latin, meaning "fibrous". These clouds are similar to cirrus uncinus, commonly known as "mares' tails"; however, fibratus clouds do not have tufts or hooks at the end. The filaments are usually separate from one another.

Like other cirrus clouds, cirrus fibratus occur at high altitudes. They can indicate an approaching warm front; however, they can also be an indication that fair weather will follow.

Google Pixel Cell Phone

Crop & contrast enhanced