A Warm–Core Disturbance in the Western Atlantic During BOMEX

Abstract

A synoptic analysis of the only tropical depression in the BOMEX data set shows it to be a kink in the Intertropical Convergence Zone. The depression has a warm core through the troposphere to at least 250 mb, and strongest circulation in and just above the boundary layer. At 250 mb, an anticyclonic wind field lies above the depression. Divergence, vorticity, and relative humidity fields, as well as cloud patterns, corroborate a dynamical picture of the depression wherein air rising in a warm core is associated with convergence and cyclonic vorticity resulting from a kink in the ITCZ. The picture is compatible with the CISK mechanism.