Intercomparison between the observed and modeled 21 January 2010 low topped tornado producing thunderstorm in Huntsville, AL

On 21 January 2010 an EF-2 tornado cut a 10.6 km path across the northern end of Huntsville, AL. This tornadic storm developed from a low topped (8 km) supercell environment characterized by low convective available potential energy (CAPE; 1000-1500 J/kg), relatively high dew points for mid-January into the mid to upper 50s, and high wind shear. High spatial and temporal observations of the tornadic supercell are analyzed using UAHuntsville's Advanced Radar for Meteorological and Operational Research (ARMOR) and the North Alabama Lightning Mapping Array (NALMA). Large raindrops were located along the western flank of the thunderstorm, with mean drop diameters between 3-4 mm just prior to the development of the tornado. Also, very little total lightning (in cloud and cloud-to-ground) was observed despite observed reflectivity values greater than 45 dBZ above 7 km. Two idealized, cloud-resolving numerical model simulations (one with terrain and one without) are used to explore storm behavior in detail and to evaluate the relative contribution of the environmental sounding and local topography on the storm's overall evolution. Comparisons are made between radar inferred and model derived reflectivity and microphysical structure in order to understand the physical processes governing this tornadic low topped supercell.