X-band Radar Observations of the 16 May 2015 Tipton, Oklahoma EF3 Tornado using the Atmospheric Imaging Radar

On 16 May 2015, an EF3 tornado impacted areas of Elmer, Tipton, and Snyder, Oklahoma.  During the mature stages of the tornado, the Atmospheric Imaging Radar (AIR) was collecting 20x105-degree volumes at 7-s temporal resolution and 12-km range.  The AIR is a mobile, X-band, imaging weather radar that utilizes digital beamforming to achieve high temporal and spatial resolutions.  The AIR revealed rapid changes in reflectivity and radial velocity estimates at various stages of the tornado’s lifecycle, including changes in weak echo hole (WEH) structure, reflectivity rings within the tornadic circulation, and a series of multi-mesocyclone interactions and rear-flank gust front surges.  Shrinking and broadening of the WEH, especially in the lower portions of the mesocyclone, indicated the potential for rapid changes in debris loading.  Changes in the WEH and the vertical structure of small-scale reflectivity rings are quantified in time and space, and these changes are compared to changes in the radial velocity field.  Comparisons with a nearby WSR-88D with polarimetric capabilities are made in order to develop relations between AIR observations and the observed WSR-88D tornadic debris signature.  Possible analyses include axisymmetric wind retrievals and investigation of Doppler spectra during times of increased debris.