Bay would fuel storms devastation
© St. Petersburg Times
published August 24, 2002
It's the worst-case scenario: a powerful storm on a northeast track heading straight for Tampa Bay.
What would happen?
That's the question emergency planners posed to the National Hurricane Center. The computer-generated image you're looking at is one answer.
It shows the potential flooding from a storm about the size of Hurricane Floyd, which ravaged the North Carolina coast in September 1999, killing 57 people. It was bigger, deadlier and almost as fierce as Hurricane Andrew, but not as costly.
It follows the same track as the unnamed hurricane that hit Tarpon Springs in 1921, the last time Tampa Bay took a direct hit from a hurricane.
Under this scenario, high winds create a storm surge causing massive flooding, particularly in Hillsborough County, where nearly the entire Interbay Peninsula would be underwater.
That may seem odd. Aren't the Pinellas beaches more vulnerable? The reason lies in the track of the storm, the counter-clockwise rotation of the winds, the shallowness of the Gulf of Mexico and the bay itself.
Hurricane experts call it the funnel effect.
The shallowness of the gulf makes Florida's west coast particularly vulnerable to hurricane-driven storm surge, said Brian Jarvinen, hurricane storm surge specialist with the National Hurricane Center in Miami.
In Atlantic storms, a lot of the energy produced by a hurricane is absorbed by the ocean. But in a gulf storm, the energy hits bottom, churning water toward the shoreline, Jarvinen said. That creates an even bigger problem if the storm is headed toward Tampa Bay.
"The added impact of the bay creates a funneling effect," Jarvinen said. The churning water surges into the bay, washing over the farthest point.
A computer model Jarvinen created shows flooding up to 17 feet above sea level in parts of Pinellas and Hillsborough.
"Certainly the impacts there are incredible, there's no doubt about it," said Jarvinen. "There's no doubt in our mind that someday we will see a storm like this and create that type of flooding. The question is when, but someday it will occur."
-- TOM SCHERBERGER