A vortex merger in which an SVC-supported circulation develops in a high-end SVC on May 6, 2015. The Bridge Creek EF3 tornado is ongoing (far left). The SVC-supported circulation moves southward and then southeastward along the SVC corridor, until reaching the tornado (far right two panels). The Bridge Creek EF3 tornado markedly strengthens after the vortex merger (far right). The track of this SVC-supported circulation is similar to the track of the SVC-supported tornado for the El Reno EF5 case. This gives us confidence that the study’s location of the SVC is correct, along the eastern edge of the hook’s precipitation gradient.