prefrontal squall line

prefrontal squall line

[prē′frənt·əl ′skwȯl ‚līn]
(meteorology)
A squall line or instability line located in the warm sector of a wave cyclone, about 50 to 300 miles (80 to 480 kilometers) in advance of the cold front, usually oriented roughly parallel to the cold front, and moving in about the same manner as the cold front. Also called nonfrontal squall line; pre-cold-frontal squall line.