A storm characterized by sudden and violent gusts of wind. A squall line is a cluster of storm-bearing convection cells along a non-frontal line, or belt; see Wang and Carey (2005) Monthly Weather Rev. 133, 6. Squall lines form along an occlusion, along an inversion created by a flow of maritime air over a cool surface, or below an upper-air trough (López (2007) Atmos. Res. 83, 2–1). Mohr et al. (2003) J. Hydromet. 4, 1 define squall line as a convective line with a trailing stratiform cloud anvil.