Baroclinity and Mesocyclogenesis in a Simulation of the VORTEX2 18 May 2010 Dumas, Texas Supercell

On 18 May 2010, VORTEX2 teams intercepted a supercell that produced a series of tornadoes near Dumas, Texas. As the storm approached Dumas, the Doppler on Wheels 7 (DOW7), DOW6, and Shared Mobile Atmospheric Research & Teaching Radar 1 (SR1) mobile radars, along with the KAMA WSR-88D, observed the formation and evolution of a long-lived low-level mesocyclone with complicated substructure. In situ measurements within this mesocyclone were obtained with 12 StickNet surface probes spaced 2-5 km apart.

To help us understand how the low-level mesocyclone and sub-mesocyclone-scale vortices formed, we are reconstructing the Dumas storm in a numerical cloud model. Currently, we are assimilating DOW7, DOW6, SR1, and KAMA radar data into the Weather Research and Forecasting (WRF) model with the Data Assimilation Research Testbed (DART) ensemble Kalman filter (EnKF). We are using the StickNet observations to evaluate the realism of the simulations, in terms of representation of baroclinic zones and mesocyclone structure. At the conference, we will report on (1) the reconstruction of the Dumas storm through storm-scale radar-data assimilation and (2) the diagnosis of low-level mesocyclogenesis in the simulations.