SciTech

NC researchers seeking early warnings for rip currents

Rip currents – like this one at Kill Devil Hills – are difficult to spot for the average beachgoer. Here, the foam in the flat spot between the breaking waves rides the rip current off-shore.
Rip currents – like this one at Kill Devil Hills – are difficult to spot for the average beachgoer. Here, the foam in the flat spot between the breaking waves rides the rip current off-shore.

While a puzzling uptick in shark attacks has secured a relentless latch on beachgoers’ fears this summer, scientists hope to ease our minds concerning another one of the ocean’s deadly lurking hazards – rip currents.

Researchers are narrowing in on a way to forecast them with the same accuracy as meteorologists who predict the chances of afternoon rain showers.

Experts behind the new rip current forecast model say it will be able to estimate the likelihood of a dangerous rip current in a particular location at three-hour intervals for 90 hours out.

It’s an advancement that could save lives. Each year, more than 100 people die as a result of rip currents, which are responsible for more than 80 percent of rescues by beach lifeguards, according to the U.S. Lifesaving Association.

Until now, rip currents have been difficult to predict because of their transient nature.

“On the East Coast, like in beach towns here in North Carolina, you get these rip currents that kind of pop in random places and hang around a handful of minutes and then just go away,” said Dylan McNamara, associate professor of physics and physical oceanography at UNC Wilmington.

Today, the National Weather Service advises on the likelihood of a rip current by issuing a low, moderate or high-risk recommendation. But it’s not a forecast, said Greg Dusek, an oceanographer at NOAA.

“It’s really been more of just guidance based on looking at the conditions as they are right at the moment,” Dusek said. “It really probably hasn’t changed much how they’ve done it in the past 20 years or so.”

The new model for forecasting rip currents uses advanced computer modeling that takes into account water and wave levels. It marries that with data from other research,such as GPS drifters used to study rip-current behavior, and information compiled through hundreds of rescue reports from expert eyewitness, such as lifeguards.

The computer analyzes the crunched data and gives a percentage for the likelihood of a hazardous rip current.

Accuracy at Kill Devil Hills

The model has proved more accurate than traditional National Weather Service methods in its test location, Kill Devil Hills, said Dusek, who plans to expand testing to include other beaches along the East Coast. Next up is the test office at Morehead City, which oversees most of the Outer Banks.

Once the model is thoroughly validated at different locations, Dusek anticipates it will become a welcome asset for forecasters to keep beaches safe.

“Hopefully, next summer or possibly the summer after that it would be used as an actual tool for the public in some capacity.”

Until then, experts advise beachgoers to be smart, heed recommendations from the NWS regarding rip currents, swim in guarded beaches and if you are caught in a rip current, swim parallel to the shore until you’re out of the current.

“If you just keep your cool, you’ll find that eventually it’ll be done with you, and then you can just swim back to the beach,” said McNamara.

See someone caught in a rip current?

One-third of drowning victims are actually would-be rescuers who overexert themselves and become fatigued. Never attempt a rescue without a flotation device. “Anything that they can depend on, and the victim can depend on, when they get overexerted,” said Spencer Rogers, a coastal specialist with N.C. Sea Grant.

Improvise, if need be, with common items typically found at the beach:

▪  a surfboard

▪  a boogie board

▪  a cooler

▪ a foam noodle

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