4 years ago today, I was documenting Project Vortex 2, a massive science project to study tornadoes, near Deer Trail, Colorado. I had the fortune of getting to snap this shot of Tim Marshall, one of the best storm chasers I've met. Besides being one of the original "founding fathers" of storm chasers, he's an engineer who has done scores of damage surveys for the National Weather Service and helped to come up with the Enhanced Fujita scale for tornado strength.