A vocabulary of landscape — a landscape of words 1083 entries

banner cloud

BAN-er KLOWD
A cloud that streams from only one side of a mountain summit, like a flag. Formed not by moisture carried over the peak but by air drawn up the lee side into lower pressure. Everest often has one. Flat ridges do not.
Etymology
Descriptive English compound. banner (from Old French baniere, “flag, standard”) + cloud.