Hurricanes: Packing a Punch Click here to listen

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Well, summer is here and it'll soon be for the Atlantic seaboard to batten down the and prepare for another hurricane season. I'm Jim Metzner, and this is the Pulse of the Planet. What begins as a cluster of thunderstorms building along a low-pressure area, is termed a storm when its winds reach miles an hour. Jay Barnes, author of several books on hurricane history, tells us at what a XXXXX storm turns into a hurricane.

"Well, by definition, a hurricane has winds of 74 miles per hour or greater. As these tropical systems over a period of days their winds gradually increase - if the environmental factors are just right - and if they're able to build into a storm, the winds pick up, they can ultimately reach that. Of course, the winds in a hurricane can far that going up to the most storms of over 155 miles per hour, which are events fortunately."

A typical hurricane might average 300-400 miles in diameter. But even with this size, it is the so-called "eye wall" that packs the biggest punch.

"The most part of a hurricane is what's known as they eye wall. This is the the area just on the perimeter of the center of the storm, the calm eye that we are familiar with that we when we track a storm moving across the ocean. The eye wall is where we'll find the highest winds and we'll also, as the storm makes landfall typically, see the highest storm right there around the perimeter of the eye."

Hurricanes tend to change in from minute to minute and hour to hour, making their strength difficult to accurately over time. We'll hear more about hurricanes in future programs. Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.