A mesoscale vortex couplet observed in the trailing anvil of a multicellular convective complex

The evolution of the circulations was captured by dual-Doppler radar observations for 1.4 hours. The primary mechanism responsible for the formation of the observed vortices was the interaction of the larger-scale flow with low level momentum transported to higher levels by multiple convective updrafts. As a consequence, vertical shear of the horizontal wind was important to initial vorticity production. The vorticity generated in this matter was subsequently increased in strength due to middle level convergence. When the convection weakened and dissipated, the primary source of vorticity was removed, and because this was an unbalanced circulation on a scale less than the Rossby radius of deformation, the vortex broke up and spun down. -from Authors