NUMERICAL STUDY OF A TORNADO-LIKE VORTEX IN A SUPERCELL STORM

The Canadian Mesoscale Compressible Community model (MC2) is used to simulate tornadogenesis at 30m grid spac-ing. The simulation is initialized with proles of a horizon-tally homogeneous thermodynamic sounding with a CAPE of 2100 J/Kg and horizontal winds similar to those in Wicker and Wilhelmson (1995). The simulation reproduced the main features of conceptual models of tornadic supercell storms, including the forward ank downdraft (FFD), the rear ank downdraft (RFD), and a hook echo shaped reectivity region surrounding a cy-clonic rotating updraft. A tornado like vortex developed in the hook echo region, within the vertical velocity gradient between the updraft and RFD and a zone of strong hori-zontal shear. This tornado like vortex developed maximum winds of 91 m/s (F3 tornado in the Fujita scale rating) and a minimum pressure of 927mb. 1