Volumetric Supercell and Tornado Analysis with Six-Second Temporal Resolution Using the Atmospheric Imaging Radar

The Atmospheric Imaging Radar (AIR) is a mobile imaging weather radar system designed and built by the Advanced Radar Research Center (ARRC) at the University of Oklahoma. By utilizing a vertical 20-degree fan beam on transmit, as well as 36 receiving elements, digital beamforming techniques can be used in order to form simultaneous RHI scans. Horizontal pedestal rotation allows for sector scans in quickly evolving weather situations, resulting in full volumetric updates on a storm of interest every six seconds. This unprecedented combination of spatial and temporal resolution was deployed on a series of tornadic supercells near Carmen, OK on April 14, 2012, resulting in the full observation of tornadogenesis and dissipation of two tornadoes at close range. With volumetric data at such short intervals, a number of supercellular and tornadic structures and evolutionary characteristics were observed in new ways. A discussion of features that were unobservable with previous methods of radar scanning techniques is presented. Specifically, volumetric vortex tilt, as well as highly detailed storm evolutions, such as mesocyclone occlusion occurring on the order of seconds, are shown.