The destructive potential of a hurricane is most commonly measured by its wind speed.
But people are much more likely to die in flooding caused by the storm, particularly along the coast, where tides surge into streets, homes and businesses. That’s a challenge for weather forecasters and emergency managers as they urge people to get prepared for a storm.
“How do we get people to understand that it’s water, not wind, that’s killing them,” said Jamie Rhome, who heads the National Hurricane Center’s storm surge unit.
Rhome was in Raleigh on Thursday to demonstrate new tools the hurricane center is developing to help people better see a storm’s flood potential. The first are digital maps that much more precisely than before show where storm surge flooding is expected along the coast.
The maps will appear on the National Hurricane Center’s website, along with other information about the expected path and wind speeds of a particular storm. The maps will be regularly updated. Not only will the public have access to them, but local officials will be able to use them to make decisions about evacuations and road closures, Rhome said.
“This will make your life so much easier and so much faster,” he told a gathering of local emergency management officials at the N.C. Emergency Operation Center on Thursday.
The second tool is a storm surge watch and warning system that will show graphically where “life-threatening” flooding – at least 3 feet above ground level – is possible. A storm surge warning, Rhome said, would signal to people that they need to do something to protect themselves, such as evacuate.
The National Weather Service is testing the warning system this year and expects to put it to use in 2017, Rhome said.
Drew Pearson, the emergency management director in Dare County, said a storm surge warning could help him and local officials make a case to residents that they’d better seek higher ground before a storm arrives.
“This is an amazing tool to have,” Pearson said. “It’s going to be life-saving. It has that potential.”
Rhome noted that about 80 percent of the 2,544 people killed in tropical storms and hurricanes in the U.S. between 1963 to 2012 died in flooding, more than half of them in storm surge. By contrast, wind accounted for less than 10 percent of fatalities.
The Hurricane Center’s new storm surge products are part of a broader effort to not only improve weather forecasts but present them in ways people can more easily understand and take to heart.
N.C. State University professor Gary Lackmann told the emergency managers that there’s great potential in taking visualization software used in video games and movies and applying it to weather forecasting. He said financial and technical hurdles remain, but it’s possible for forecasters to make “photo realistic” weather predictions that show, on the ground, what a heavy rain or storm surge might look like in a particular location.
“Every time you watch a movie, it’s being done,” Lackmann said. “It’s just not being done with storm forecasting yet.”