Saskatchewan's Tornado Hunter launches new book

A new book by Saskatchewan'sfamous tornado hunter looksto the sky for answers.

Greg Johnson's new book Why is the Sky Green? was launched last week in Saskatoon.

"The title of the book was born out of a single photograph that I took in 2015 in Manitoba and it was enormous, I mean enormous tornado touched down," Johnson said on CBC's Saskatchewan Weekend.

In that photo, the sky was a beautiful, terrifying shade of green.

Johnson explained that it's also the question he gets asked the most: "Does the sky really turn green right before a tornado hits?"

"When a storm is full of rain, it is actually very dense and the light can't penetrate it and it looks black to our eyes," Johnson explained.

As the rain turns to hail, it becomes less dense and the light begins to penetrate through, changing the colour to green.

"A better question is 'what should I do if the sky is green?' Get underground, take some cover," Johnson said.

Johnson has been chasing storms across North America for a decade. Through that time he's seen the massive destruction of storms but also the intense resiliency of people.

"We think of that as being a real tragedy but the best of humanity, really the best of people, come out in the face of tragedy," he said.

In hisnew book, Johnson features some of the most beautiful and memorable moments of those journeys.

It's available on the Tornado Hunters website.