New Maps Aim To Raise Awareness Of Storm Surge Danger

Hurricane season begins Saturday, and the National Oceanic and Atmospheric Administration (NOAA) are forecasting an active season, with perhaps 7 to 11 hurricanes.

With memories of last year’s destruction from Hurricane Sandy still fresh, meteorologists are working on ways to improve the way they forecast storms and communicate warnings to the public.

When Sandy was making its way northward in the Atlantic and began to turn toward the East Coast, the National Hurricane Center tried to emphasize the danger storm surge posed for residents, especially those near New York City. They warned of six to eleven feet of storm surge and floods above ground level.

As it turned out, the Hurricane Center’s forecast was on the money. Rising sea water, pushed by Sandy’s powerful winds, came ashore and brought widespread flooding to New Jersey, Long Island, parts of Brooklyn and Staten Island, where Rosemary Caruso was living, just a block from the water.

“It was like the ocean came up on land,” she says.

Underestimating Storm Surge

This wasn’t the first time a storm had flooded Staten Island. There were storm surges in the 1930s, but back then many of the coastal areas were still undeveloped marshland.

When Sandy hit, despite warnings, thousands in vulnerable neighborhoods didn’t evacuate. More than 20 people died on Staten Island, most from drowning. Jamie Rhome, a storm surge specialist at the National Hurricane Center, says it’s a problem seen in nearly every hurricane.

“In general, this nation does not understand storm surge. Nor does it understand its vulnerability,” Rhome says. “We’ve seen poll after poll of individuals, right at the coast, saying they’re not vulnerable to storm surge.”

It’s a threat that Sandy showed is not limited to states along the Gulf and in the southeast.

“The New York area is, what I think, one of the most vulnerable areas in the entire East Coast,” says William Fritz, a geologist and president of the College of Staten Island.

Months before Sandy, Fritz worked with colleague Alan Benimoff to map areas on the island vulnerable to storm surge. The map proved prescient. The morning after the storm, Benimoff was out on Staten Island charting the surge. In some neighborhoods, he says it reached 14 feet.

“It was terrible. I never saw anything like it,” Benimoff says.

Sandy’s storm surge matched almost exactly Fritz and Benimoff’s model. With the help of supercomputers at the University of North Carolina, Fritz says his team now is prepared to do real-time modeling to understand the threat of storm surge as a hurricane approaches.

The problem, he says, is that public awareness of the threat of storm surge now lags behind science’s ability to forecast it.

“Some of the people that lost their lives … were a few blocks away from safe ground,” Fritz says. “But they didn’t know … where the safe ground was.”

Fritz is calling for a public education campaign similar to that used in the northwestern U.S. for tsunamis; one that would include signs identifying surge-prone areas and the nearest high ground.

Remapping The Threat

Learning from the experience of Sandy, Florida’s Miami-Dade County has recently drawn up new maps dividing the county into five evacuation areas now relabeled “storm surge zones.”

The new maps have tripled the number of people who live in areas that could potentially be evacuated. Emergency Management director Curt Sommerhoff says that’s nearly two million residents — most of the people who live in Miami-Dade County.

“We’re in the most hurricane-prone area of the most hurricane-prone state in the United States,” Sommerhoff says. Since Florida is a peninsula, he says, it faces storm surge threats on three different fronts.

In a hurricane, emergency managers advise residents to shelter in place when at risk from high winds. But storm surge that causes the most damage and which takes the most lives, and that’s why they say to evacuate.

Efforts to get that message to the public are also underway at the National Hurricane Center. One of the new tools is graphics and mapping software designed to be read and easily understood by the public.

Instead of technical terms like “height above mean sea level,” the map tells coastal residents how deep the water is likely to be in their neighborhoods. The center’s Jamie Rhome, who helped design the software, says, its color coded.

“The brighter the color, the deeper the water has the potential to be,” Rhome says. “But more importantly, people don’t understand how far the water goes inland. This map clearly shows how far the water goes inland. If you’re in one of those colored areas, you need to do something to protect your life.”

The new storm surge maps were intended to be ready by next year. National Hurricane Center officials say, because of the need and strong demand by emergency managers, they hope to begin using them this summer.

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