Mesoscale convective vortices observed during BAMEX, Part I: Kinematic and thermodynamic structure

The study of MCVs spawned from organized convection constituted a major component of BAMEX. In all, five mature MCVs were sampled with dropsondes. Data from the NOAA P-3 were available for two MCVs and data from the ground based platforms were available for two other cases. In this talk we first review the convection that gave rise to these MCVs and the attendant synoptic-scale conditions. We then present analysis of the kinematic and thermodynamic structure of each MCV, comparing vertical motion, longevity, vertical structure, horizontal scale, tilt, environmental wind shear and conditional instability. We will then summarize the MCV characteristics in terms of some simple parameters that succinctly define their properties and simplify the interpretation of the convection associated with these vortices (emphasized in Part II). Preliminary analysis indicates that the five cases sampled represented a wide range of intensity, ambient wind shear, and thermodynamic stability. In most cases the vortices clearly penetrated to the surface and through their horizontal wind fields induce significant differential advection of temperature and moisture in the boundary layer. In some cases, this advection, combined with favorable wind profiles induced by the MCV, promoted severe convection in an otherwise benign environment.