Any non-frontal line or narrow band of active thunderstorms. The term is usually used to describe solid or broken lines of strong or severe thunderstorms.

Related Articles:

• Hailstorms hailstorm Brisbane wild hail video footage storms November 16 2008
• Glossary: Tail-end Charlie
• Severe Storms Southern Tablelands 4th December 2014
• Squall line storm event New South Wales and Sydney - 1 February 2021
• Supercell then a squall line Sunday in SD. Lots of colors, lightning, a fun day....