Doppler Radar Observations of Vortices in a Left-Moving Supercell Thunderstorm on 26 May 2009

Two Doppler on Wheels (DOW) radars observed a left-moving nontronadic supercell on 26 May 2009 near Dallas, TX, during the first field phase of the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2). Single-Doppler observations began while the storm was a left-moving supercell and continued for approximately half an hour, after which time a second radar also began scanning the storm. During the entire period of single-Doppler observations, as well as the first fifteen minutes of dual-Doppler observations, numerous vortices were observed in the southwestern portion of the storm. These vortices were most notable between 3 and 5 kilometers in height, but existed from 1.5 to above 6 kilometers, which was the highest altitude at which the radar scanned. These vortices varied widely in strength, depth, temporal continuity, and size and rotated both cyclonically and anticyclonically. The strongest vortex observed had a ΔV of 53 m s^-1 and was about 5.7 kilometers in diameter. These vortices grew less numerous in time and eventually dissipated as a wind shift propagated through the core of the storm. As this occurred, the storm began to take on right-moving characteristics.-1-2013-->