| description abstract | The mean genesis environment was constructed for each of five mesoscale convective complex (MCC) population centers around the world: Africa, Australia, China, South America, and the United States. It is found that the environments are very similar and exhibit many of the same dynamic and thermodynamic structures that are present with systems in the United States. In particular, MCCs initiate within prominent baroclinic zones characterized by locally large values of lower-tropospheric vertical wind shear and convective available potential energy (CAPE). Typically, a low-level jet of air with low static stability, high equivalent potential temperature, oriented nearly perpendicular to the baroclinic zone, intrudes into the genesis region and is forced to ascend over a relatively shallow, surface-based layer of relatively cool air. Pronounced warm advection accompanied by strong lower-tropospheric veering overlays the surface-based cool layer. A local maximum in absolute humidity and a local minimum in static stability mark the favored region for formation of the convective system. Low-level convergence, upper-level divergence, and an approaching midlevel vorticity maximum associated with a weak short-wave trough are also typical of the mean genesis environment. | |
