FLANKING LINE

A line of attached cumulus or towering cumulus clouds of descending height, appearing as stair steps (usually on the southwest side) of the most active part of a supercell.

A line of cumulus or towering cumulus clouds connected to and extending outward from the most active part of a supercell , normally on the southwest side. The line normally has a stair-step appearance, with the tallest clouds closest to the main storm, and generally coincides with the pseudo-cold front . See Picture and