Using data collected after Hurricane Charley, researchers at the University of South Florida are looking at storm surge… or in Charley’s case… why there wasn’t more. Storm surge is an abnormal rise in sea level associated with hurricanes. As Charley approached Charlotte County – emergency managers were concerned that low-lying areas would be in trouble. Even before last hurricane season, oceanographer – Robert Weisberg – had been running computer models to see what affect the size of a storm, its strength and direction have on surges. When Charley, hit Weisberg ran his earlier model… and it turned out to be quite accurate. He says there’s no single factor which determines storm surge…

“It’s not that simple…not only does the surge elevation depend upon the storm category…or how fast the winds are moving…but it also depends where the storm hits…from which direction it approaches…how fast it approaches…and also what the diameter of the eye really is.”

Weisberg says Charley’s fast moving, southerly approach made for a relatively mild storm surge - and that where it made landfall also played a role. He says if Charley had come ashore a bit further north, storm surge would’ve likely been far worse. Weisberg’s model also explains why North Captiva Island was split in two… He says when Charley approached, the sea level was substantially lower on the gulf side than on the inter-coastal side… but then as the storm blew through, that imbalance was suddenly, and forcibly reversed...

“So what happened is you have this very narrow low-lying area in North Captiva Island where this water level difference was the largest…and once the gulf water kinda overtopped the island…and just washed the sand right out.”

Weisberg says he hopes his research will help add more detail to storm surge arnings…although his department doesn’t make official recommendations. That’s up to the National Hurricane Center.