A complete analysis of tornadogenesis for the January 21, 2017 tornadic supercell at Hattiesburg, Mississippi. This event was close to the 208 case average. In panel 2, a cell merger and associated outflow instigate the RFD surge and DRC. The RFD surge pushes into the inflow sector of the supercell (panel 2 and 3), creating the inflow channel and SVC, discussed extensively in section 6. The nose of the DRC approaches the RFD occlusion from the southwest and wraps into the circulation just as the tornado starts (panel 4). A second circulation develops near the RFD boundary to the southeast of the inflection point (panel 4). This circulation is absorbed into the RFD, merging with the tornado about three minutes after the tornado start time, markedly strengthening the tornado (panel 5 and 6).