Damage Survey Analysis of the 20 May 2013 Moore Tornado
A photogrammetric analysis of the tornado structure was superimposed on the damage track. It showed the visual funnel diameter scaling with EF1-2 damage. The funnel diameters and analysis of fallen trees illustrated convergent flow into the visual funnel before turning tangential. This implies strong vertical velocities. In addition, dual-polarization radar showed a well defined tornado debris signature; although there were times where the correlation coefficient (ρhv) minimum did not collocate with the reflectivity maximum (dz). It is hypothesized that the result is due to the entrainment of raindrops into the tornado.
Supplementary URL: http://apollo.lsc.vsc.edu/vortex2/Moore2013/index.html