Editing Squall line (section)

===Characteristics===
{{unreferenced|section|date=February 2024}}
[[File:Ligne de grain.svg|thumb|lang=en|upright=1.5|Cross-section of a squall line showing precipitation, airflow, and surface pressure]]

====Updrafts====
The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an [[updraft]], rising from ground level to the highest extensions of the [[troposphere]], condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to [[synoptic scale meteorology|synoptic scale]] winds). Because of the chaotic nature of updrafts and [[downdrafts]], pressure perturbations are important. [[Precipitation]] cooled air from downdrafts usually outwardly just above the surface and lifts air into the updrafts unless gushing too far out and cutting off this [[Inflow (meteorology)|inflow]]. Visually this process may take the form of a [[shelf cloud]], often with a turbulent appearance.

====Pressure perturbations====
Pressure perturbations around thunderstorms are noteworthy. With [[buoyancy]] rapid within the lower and mid-levels of a mature thunderstorm, updraft and downdraft create distinct mesocenters of pressure. As thunderstorms organized in squall lines, the northern end of the squall line is commonly referred to as the cyclonic end, with the southern side rotating anticyclonically (in Northern hemisphere). Because of the [[Coriolis force]], the northern end may evolve further, creating a "comma shaped" wake low, or may continue in a squall-like pattern. The updraft ahead of the line create a [[mesolow]] too while the downdraft just behind the line will produce a mesohigh.

====Wind shear====
[[Wind shear]] is an important aspect of a squall line. In low to medium shear environments, mature thunderstorms will contribute modest amounts of downdrafts, enough to help create a leading edge lifting mechanism – the gust front. In high shear environments created by opposing low level jet winds and synoptic winds, updrafts and consequential downdrafts can be much more intense (common in supercell [[mesocyclone]]s). The cold air [[outflow (meteorology)|outflow]] leaves the trailing area of the squall line to the mid-level jet, which aids in downdraft processes.