It’s no secret that tropical storms and hurricanes create damaging winds and cause heavy rainfall that can lead to deadly flooding. But what may be less obvious is that the storm surges they create can be equally devastating, often posing the greatest threat to life and property along coasts.
A storm surge is an abnormal rise of water generated by a storm, on top of predicted astronomical tides, according to the National Hurricane Center† It is caused when the force of the wind moving cyclonicly around the storm pushes the water toward the shore.
The height of a storm surge depends on a storm’s size, forward motion and angle of attack, as well as the depth of the shoreline, said Dennis Feltgen, a meteorologist and spokesperson for the National Hurricane Center. A change in a storm’s track, even as small as 20 miles, can make a difference, he said, and every mile of coastline along the eastern United States and the Gulf of Mexico is susceptible to storm surge from tropical cyclones.
“A storm surge has traditionally been the leading cause of death from tropical cyclones,” accounting for about 50 percent of all direct fatalities, Mr Feltgen said.
In 2017, the National Weather Service and the National Hurricane Center began issuing storm surge warnings and warnings along the East Coast and the Gulf Coast, and in 2019 to Puerto Rico and the U.S. Virgin Islands. Since 2017, 21 tropical cyclones — including 14 hurricanes, five of which were large — have made landfall and triggered storm surge watches or warnings, he said.
In 2021, Hurricane Ida swept into Louisiana as a Category 4 storm, creating dangerously high storm surges and testing the city’s system for withstanding catastrophic flooding. Some areas along the coast experienced storm surges as high as 14 feet, according to a report from the center† It is estimated that Ida’s winds and storm surge caused about $55 billion in damage in Louisiana.
In 2008, Ike, a Category 2 hurricane that made landfall near Galveston Island in Texas, caused spikes up to 20 feet above normal tides. Property damage was estimated at $24.9 billion. And before that, in 2005, Hurricane Katrina created a storm surge 25 to 28 feet above normal tides and caused about $75 billion in damage in the New Orleans area and along the Mississippi coast.