Assessing Detection and Estimates of Low-Level Supercell Horizontal Vorticity Diagnosed from Doppler Radar Data: Simulation Study

Rotunno and Klemp (1985), Davies-Jones and Brooks (1993) and others have demonstrated that the upward tilting of intense low-level horizontal baroclinically-generated vorticity causes the development of low-level rotation in mesocyclones. Thus, the detection of large horizontal vorticity in certain locations of a supercell and in certain directions (given a favorable viewing angle) might give the radar meteorologist or forecaster an early warning of imminent tornadogenesis.

At the conference, we will assess detection and estimates of simulated low-level supercell azimuthal component of baroclinically-generated vorticity from virtual Doppler radar data. The supercell simulation was generated using the Advanced Research Weather Research and Forecasting (WRF-ARW) model with 111-m horizontal grid spacing and typical cloud model settings. A tornado develops ~110 min into the simulation and becomes very intense with surface winds briefly exceeding 110 m s^-1 (EF5).