Here's what a tornado leaves behind, as seen from the air near Birmingham, Alabama. It's a nasty trail, and the storm system killed over 300 people. The NWS picked up the tornado on radar. The debri in the vortex reflected the radar energy, which made it possible to be seen on radar. It is reported to have lifted the debri as high as 8000 feet. I have seen the radar picture, and it's sobering.