If a hurricane threatens the South Carolina coast this year, tiny submarines will be waiting.
Three or more remotely operated submarines will be pre-positioned in the path of any storm. They will zip just under the sea surface taking all sorts of measurements.
The submarines, sometimes called "gliders," are a federally funded increase of a program that provided storm forecasters a critical missing piece of data to successfully predict the track and intensity of Hurricane Florence at landfall in the Carolinas last year.
In September, as Florence bore down on the Southeast coast and computer model runs fluctuated widely, two of these type of undersea research devices were launched to take readings on the north and south sides of the storm. They found a wider variety and mix of temperatures than computer models had predicted.
More importantly, they found a previously unrecorded layer of colder water under the surface that would sap strength from Florence as the storm pulled the ocean up.
National Hurricane Center forecasters used that data to predict as early as six days out that the storm was most likely to strike where it did — in North Carolina, near the South Carolina border — and that it would weaken beforehand.
"You could think of gliders as the weather balloons in the ocean," said Catherine Edwards, the University of Georgia Skidaway Institute of Oceanography researcher who deployed those two gliders.
She worked with the Southeast Coastal Ocean Observing Regional Association, a multi-institution and agency group gathering ocean data.
“The glider data is being used in real time,” Edwards said. “These real-time observations can improve our hurricane forecasts right now, not just in a paper to be published a year from now.”
The vessels, which are about 6 feet in length, resemble torpedoes. Packed with sensors, they run on batteries and can stay at sea four to six weeks at a time. They surface periodically and literally "phone home" data using satellite phones.
The SECOORA gliders are part of a larger network of federal and research group crafts getting deployed more and more offshore for a variety of work, from hurricanes to current studies.
One of those groups is the S.C. Department of Natural Resources, which hopes to use the information to improve fishery management. A department crew retrieved the Hurricane Florence glider after the storm, when its battery ran low about 40 miles offshore Charleston.
"The current was moving very fast and not very much of it was sticking out of the water. But we got it on board with no further damages," said Bo Von Harten, the captain of DNR's research vessel Silver Crescent.
In the wake of the Florence success, the association was awarded a $220,000 grant to fund the program for two more years.
The gliders, along with data from weather buoys offshore, as well as high-tech equipment such as 3D radar aboard Hurricane Hunter airplanes, are giving forecasters clearer reads on the storms than they had even a few years ago.
The advances are coming as storms appear to be getting stronger, less predictable and, consequently, more dangerous. That makes them invaluable to people who live along the coast.
"That 15-20 mph difference in a hurricane's winds might be the difference in whether you have to evacuate," Edwards said.