Hurricane Dennis storm surge explained

TALLAHASSEE, Fla., Oct. 9 (UPI) -- U.S. scientists say they've determined why a 10-foot storm surge from Hurricane Dennis last year was about 4 feet higher than forecast.

The storm passed North Florida on July 10, 2005, causing a 10-foot storm surge in some areas along Apalachee Bay -- a higher-than-forecast surge that couldn't be explained by the local winds that conventionally drive storm surge.

Now, scientists at Florida State University and the National Oceanic and Atmospheric Administration have found the surge in Apalachee Bay was amplified by a "trapped wave" that originated off the southwest Florida coast.

The discovery of the previously undocumented storm surge phenomenon has changed how NOAA's National Hurricane Center prepares storm surge models for the Gulf of Mexico. The new modeling procedures, said forecasters, will help improve the accuracy of storm surge forecasts for the entire Gulf coast from Florida to Texas.

The research by Steven Morey, Mark Bourassa, Dmitry Dukhovskoy and James O'Brien of FSU's Center for Ocean Atmospheric Prediction Studies and Stephen Baig of NOAA's Tropical Prediction Center of the National Hurricane Center appears in the Oct. 4 issue of the journal Geophysical Research Letters.