Read the following today in Canada by Richard Ford (review forthcoming):
“I just stared at the mare’s tails in the west – the sky behind them purple and gold and bright green, turning blue in the high reaches.”
Mare’s tails? Never had heard this expression before. Googled it. Turns out it refers to cirrus clouds. Asked TLMW, who is a card-carrying member of the Cloud Appreciation Society. Drew a blank as well.
Apparently, there’s an old sailor’s expression that goes thus: “Mare’s tails and mackerel scales make tall ships carry low sails.” Mare’s tails are those hooked-shaped cirrus clouds and mackerel scales are cirrocumulus which appear as bands of fish scales. Both are high altitude clouds above 20,000 ft. When both are seen together it is a sign to the sailor of a storm front bringing in a weather change within 24 hours. Mare’s tales. Ok.
