Boiling black skies, blinding sheets of rain, and the elusive swirling twister.
Hundreds of storm chasers descend on the Great Plains to capture Mother Nature's fury every spring.
Gene Robertson is one of them.
"I was always watching the weather as a kid, I was scared to death of tornadoes," said Robertson.
Now, Robertson and his wife Barb own their own company, P.D.S. Storm Tours, leading small groups across the country to learn about thunderstorms.
"They want to see storms, they want to see storm structure, and of course the elusive tornado, which doesn't happen all of the time. It's not only having that one on one relationship with the guest but it's also helping them understand the weather, helping them understand the meteorological side of the weather. So when they go home, they can say 'oh that's this cloud, or oh that's that cloud or whatever," said Robertson.
The Robertsons provide a good example for their tour guests...they're certified storm chasers with the National Weather Service, a vital service that helps warn the public about dangerous weather.
Visual confirmation helps meteorologists verify what they're seeing on radar.
"We also have a HAM radio so we can report back to the National Weather Service...so he's got that on board. We have the anemometer so we can report back the wind speeds and things like that. We've got the live camera. The news stations can, if they choose to, pull up that live feed and they can see exactly where we're at. If they want to pinpoint down to where we're at they can actually pull that up and show the public what's going on in their area," said Barb.
Storm chasing isn't Robertson's only passion, he's a firefighter.
That side of him kicks in when approaching a damage scene.
"There's so many different hazards that are out there after the tornado comes through. You've got powerlines down, you've got gas leaks, you've got debris falling everywhere and you may come across injured people. So it's kind of having that situational awareness to know where your surroundings are," said Robertson.
Educating their guests and the public about severe weather is a top priority.
"If somebody approaches us and asks us, 'hey are you guys out storm chasing? What's going on?' We start telling them what the conditions are, what could happen. I'll ask him, 'do you have a weather radio?' If they say no, I'll just give them one. It's just that people need to be informed."
The Robertsons have led storm tours since 2010 and are looking forward to another upcoming severe weather season.
They also teach severe weather classes in addition to storm chasing tours. You can learn more aout them on their website or on their Facebook page.