Mesoscale air motions associated with a tropical squall line.

Abstract

Composites of radar and wind observations in a coordinate system attached to a moving tropical squall line confirm that such a squall system is composed of two separate circulation features: a convective squall-line region and a stratiform anvil region. The squall-line region is characterized by mesoscale boundary layer convergence, which feeds deep convective updrafts, and mid-to-upper-level divergence associated with outflow from the cells. The anvil region is characterized by mid-level convergence, which feeds both a mesoscale downdraft below the anvil and a mesoscale updraft within the anvil cloud.-from Authors