Jon Krakauer is a mountaineer and the author of the best-selling book Into Thin Air. The book is about his 1996 expedition to Mt. Everest in which numerous climbers died in a blizzard. Krakauer was not prepared for the deadly blizzard. He didn’t know it was coming. He stood on top of Mt. Everest and just saw some cloud formations and thought nothing was wrong.

Later he met another climber who had returned quickly to base camp when he saw those same cloud formations. He had hustled back down the mountain. Why? This man was a pilot. In his years flying over dangerous storms, he had come to recognize thunderhead cloud formations. He had studied them from high overhead. These are a sure sign of dangerous weather. So when he was down below a thunderhead, he recognized it instantly and turned a…