Chris, what benefit are you seeking out of your digital camera? I am not anti-digital. I own one myself. But as a long time professional photojournalist I can tell you that other than the ability to preview your photos quickly, you really aren't getting any huge benefit out of going digital, as far as storm chasing goes. Your basic Canon EOS Rebel ($150) will ultimately provide you with clearer, more reproduceable quality photographs than even the best Canon EOS-1DS ($8k) will. I know digital is all the rage, but the quality simply isn't there yet for serious photography.
I'll use my digital for spot news, snapshots, and random crap for use on the web. But for something I was actually going to sell or use for archival purposes, film is still the only way to go for serious scientific or archival image reproduction.
But if all you're really doing is taking casual snapshots for a blog, then yeah, any 3+ mp digital should give you the quality for that.