I f anyone watches this Discovery show, they appear to be using Z7 cameras. Look on the website at the behind the scenes video, and it shows the TV crews with their gear.

Storm Chasers: Behind The Chase : Videos : Discovery Channel (http://dsc.discovery.com/videos/storm-chasers-behind-the-chase/)

I believe they're using Z7s, maybe mixed with Z5s, but it's definitely HDV cameras and they use videotape. You can see "HDV" clearly written on the back of the flip-out LCD. I'm not sure if they also use the MRC1 recorder.