183 High-Temporal Resolution Observations of Weak-Echo Reflectivity Bands and Momentum Surges in the 16 May 2017 Wheeler, Texas, Tornado

Thursday, 25 October 2018
Stowe & Atrium rooms (Stoweflake Mountain Resort )
Casey B. Griffin, Univ. of Oklahoma, Norman, OK; and D. J. Bodine and J. Lujan Jr.

The Atmospheric Imaging Radar (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. On 16 May 2017 the AIR collected 7-second-resolution 110° azimuth x 20° elevation sector volumes of an EF-2 tornado that occurred near Wheeler, Texas. The Wheeler, Texas, tornado was sampled as close as 10 km in range and was approximately 1 km in diameter with maximum measured delta-v of ~90 m s-1 during the 10-minute deployment. The purpose of this study is to document the temporal evolution of the weak-echo reflectivity bands that were observed to wrap around the tornado during the deployment. Among the analyses will be simultaneously collected RHIs that show horizontal vorticity collocated with the weak-echo reflectivity bands. Additionally, this study documents how an observed momentum surge within the rear-flank downdraft modifies tornado intensity and causes asymmetry in the velocity couplet. Finally, observations of the development of an anticyclonic vortex aloft that exhibited delta-V in excess of 30 m s-1 are presented.
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