What is the name for a line of thunderstorms that forms along a cold front?

A line of thunderstorms that forms along a cold front is called a squall line. It may also form just ahead of the front and is sometimes described by meteorologists as a quasi-linear convective system, or QLCS.

Squall lines form when a long zone of rising air organizes multiple thunderstorms into a connected line. Cold, dense air spreading outward from thunderstorm downdrafts can lift warm, moist air ahead of the system, helping new cells develop along the leading edge. The result can be a fast-moving band of intense rain, frequent lightning, hail, and damaging straight-line winds.

Some squall lines bend into a bow echo, a radar shape associated with especially strong winds. In other cases, a line can contain embedded rotation and produce tornadoes, even though its dominant threat is often widespread wind damage. Over dry regions, strong outflow behind a squall line can lift dust and create a haboob.

A gust front is the outflow boundary produced by a storm or storm complex, not the entire thunderstorm line. A shelf cloud is a visible cloud feature along that boundary, while a supercell is an individual rotating thunderstorm rather than a line.