Relationship between system slope and updraft intensity in squall lines

Abstract

In recent years there has been debate about whether squall lines have an "optimal state." It has been repeatedly demonstrated that the slope of a squall line's convective region is related to the comparative magnitudes of the squall line's cold pool and the base-state vertical wind shear. The present work addresses a related assertion, that squall-line intensity ought to be maximized for an upright updraft zone. A simple demonstration shows that upright systems realize more of their buoyancy because their attendant downward-directed perturbation pressure gradient accelerations are weaker. © 2010 American Meteorological Society.