The supercell that produced the EF3 at Salyersville, Kentucky on March 2, 2012. The RFD boundary is purple and occlusion downdraft is encircled in maroon just southeast of the tornado. The nose of the occlusion downdraft is circled in blue just east-northeast of the tornado. Davies-Jones 2006, Markowski 2002, Lee et al. 2011, 2012 explain more about the occlusion downdraft.