When a major storm strikes, most people have the good sense to either hunker down or get out of the way. Storm chasers, however, are a special breed. They run right for it.
Reed Timmer, one of the stars of the hit Discovery Channel show "Storm Chasers," details his adventures around some of the world's strongest storms.
Read an excerpt from the book below, and head to the "GMA" Library to find more good reads.
The dream starts with a breeze. When I envision the complex creation of the most violent and mysterious weather phenomenon of all—a three-hundred-mile-per-hour, landscape-churning, damage-scale-topping tornado—it starts with a soothing breeze.
Here in central Oklahoma, where I really do live, and where tornadoes rated the maximum F5 on mete-orology's Fujita Scale truly have gouged the earth time and time again, the breeze comes out of the south. The air is sultry—moist and warm. When it reaches your skin, it's as thick as lotion, and it makes you feel like you've been transported somewhere exotic. You almost have. The breeze originates in the Gulf of Mex-ico, where it once washed over beachgoers.
In my mind, I watch how this special air flows—meteorologists call this movement the low-level jet—as if it were a river, a thousand feet in the sky, extending halfway across the continent to the Great Plains. When the tropical air reaches the likes of Texas, Oklahoma, Nebraska, or Kansas, something curious happens. And the air is no longer a quiet, soothing breeze.
Near the earth's surface, moist air collides with different kinds of air coming from different directions. Hot, dry air from the American Southwest and northern Mexico. Cold air from the north, blown southward across Canada, all the way from the Arctic. Such a convergence doesn't happen everywhere, but in central Oklahoma it's hardly a freak event. The Great Plains—which weather nuts like me call Tornado Alley—is a rare, natural intersecting point for all this wind. About 90 percent of all tornadoes reported annually in the United States—some eight hundred or more per year—touch down in Tornado Alley.
In the birth of my envisioned F5, all of that clashing air follows a meteorological script. The hot, dry air in-jects the atmosphere with heat that serves as a springboard for the now warm, moist air to rise. As kids, we were taught that hot air rises—hot air molecules agitate more than cold air molecules, and, needing lots of room to move, the hot air expands upward. When an F5 forms over Tornado Alley, this ascension is violent, sometimes moving at over one hundred miles per hour. The surrounding cold air only helps matters. Cold air forces neighboring hot air to rise faster.
Then, approximately a mile above the ground, the moisture in the rising air condenses into a mist. This is the meteorological equivalent of a shark fin popping out of the ocean water. It marks the beginnings of a storm cloud. It's the first visible sign of danger.