A vocabulary of landscape — a landscape of words
1469 entries
mare’s tail
Mares’ tails are cirrus clouds drawn out into long curving streaks with a hooked or tufted head and a fine tail trailing behind. They are made of ice crystals falling from a small generating head into air moving at a different speed, so the tail is a record of wind shear written across the sky. They sit at 20,000 feet and up.
Etymology
The English name is old, descriptive, and used by sailors. The formal name for the type is cirrus uncinus, Latin for hooked curl, which is the same observation made twice. The tails themselves are called fallstreaks.