Crab etc
I accept your hit............
There was a wonderful MetMan on HERMES who one morning presented us with a Black and White OHP (remember those?) slide of the weather systems around us.
There was a very deep low to the west of us, heading in our direction.
His opening words were........
"In meteorological terms, this is known as a "Zebra's Arsehole".."
Very clear, very explicit, and absolutely correct!