The 8 May 2009 Superderecho: Analysis of a real-time explicit convective forecast

The simulation was able to reproduce many of the key attributes of the observed system, including an intense [~100 kt (51.4 m s-1) at 850 hPa], 10-km-deep, 100-km-wide warm-core mesovortex and associated surface mesolow associated with a tropical storm-like reflectivity eye.

A detailed analysis suggests that the simulated convection develops north of a weak east-west lower-tropospheric baroclinic zone, at the nose of an intensifying low-level jet. The system organizes into a north-south-oriented bow echo as it moves eastward along the preexisting baroclinic zone in an environment of large convective available potential energy (CAPE) and strong tropospheric vertical wind shear. Once the system moves east of the low-level jet and into an environment of weaker CAPE and weaker vertical wind shear, it begins an occlusion-like phase, producing a pronounced comma-shaped reflectivity echo with an intense warm-core mesovortex at the head of the comma.