Aerial Damage Survey of the 2013 El Reno Tornado Combined with Mobile Radar Data

AbstractA detailed damage survey of the El Reno, Oklahoma, tornado of 31 May 2013 combined with rapid-scanning data recorded from two mobile radars is presented. One of the radars was equipped with polarimetric capability. The relationship between several suction vortices visually identified in pictures with the high-resolution Doppler velocity data and swath marks in fields is discussed. The suction vortices were associated with small shear features in Doppler velocity and a partial ringlike feature of high spectral width. For the first time, a suction vortex that created a swath mark in a field was visually identified in photographs and high-definition video while the rotational couplet was tracked by radar. A dual-Doppler wind synthesis of the tornadic circulation at low levels near the location of several storm chaser fatalities resolved ground-relative wind speeds in excess of 90 m s−1, greater than the minimum speed for EF5 damage. The vertical vorticity analysis revealed a rapid transition from a s...