High-temporal Resolution Observations of the 27 May 2015 Canadian, Texas, Tornado using the Atmospheric Imaging Radar

On 27 May 2015, the Atmospheric Imaging Radar (AIR) collected high-temporal resolution radar observations of an EF-2 tornado near Canadian, Texas. The AIR is a mobile, X-band, imaging radar that uses digital beamforming to collect simultaneous RHI scans while steering mechanically in azimuth to obtain high-temporal weather data. During this deployment, 20º-by-80º sector volumes were collected every 5.5 s at ranges as close as 6 km. The AIR captured the late-mature and decaying stages of the tornado. Early in the deployment, the tornado was 1 km in diameter and exhibited maximum Doppler velocities near 65 m/s.

This study documents the rapid vortex structure changes associated with the dissipation stages of the tornado. Axisymmetric analyses will be used to interrogate changes in tangential flow and reflectivity structure associated with a decreasing tornado core diameter and a transition from a two-cell to a one-cell vortex flow. Additionally, temporal changes in Delta-V and a high-temporal resolution angular momentum budget will be presented. Finally, the temporal evolution of circulation over a range of areal extents will be studied in order to understand how the spatial distribution of vorticity changes in time.