Anatomy Of A Hurricane

A woman listens the radio as others wait inside a shelter in Kingston, Jamaica, as Hurricane Ivan approaches the country, Friday, Sept. 10, 2004.
Just four weeks ago, Hurricane Charley's last-minute hard-right turn and its surge from a Category Two to a Category Four storm was proof of any hurricane's unpredictability, reports CBS News Correspondent Mark Strassmann.

Now comes Ivan -- following Charley's path almost exactly, and already a Category Four.

To John Kaplan, a researcher in the fuzzy science of hurricanes, Charley was a reminder.

"There are so many things that can change so quickly," he said.

These storms usually start off Africa, feeding off the warm Atlantic waters, and warm, wet summer atmosphere.

The eye forms and draws in outside winds. Thunderstorms drive it on. The eye tightens, and the winds whip faster and faster.

Think of it like a spinning figure skater. The closer the skater wraps his/her arms around his/her body, the faster the spin.

"Your radius is getting smaller, and therefore your speed has to get, the rotation has to get higher. And it's the same thing with the winds," Kaplan explained.

To sustain a hurricane, ocean waters have to be at least 80 degrees.

Hurricanes become especially devastating, as Ivan was to Grenada, when they pass over even warmer water -- like the Caribbean, or the Gulf of Mexico, where water temperature is in the upper 80's.

Ivan is now reaching a critical point near Cuba, including a vast stretch of warm water that lies ahead.

"As the storm increases, it's like one big gas station?" asked Strassmann.

"Pretty much. Yeah. And the gas is increasing here. So there's much more gas here than there is now actually," replied Kaplan.

But if Ivan cools down and slows down over Cuban soil, Floridians could dodge an ugly storm.

If it's more like Charlie, the state could be in for a three-peat of destruction.