Program seeks to predict waves during storm
USGS coastal change forecast model will warn of high water
RALEIGH, N.C. — When John Couch is certain a storm will hit Hatteras Island, he goes into action, moving merchandise in his auto parts store from bottom shelves to top ones and hauling away the most valuable items.
But at 64, Couch is less enamored of spending eight hours packing up property. So his ears perked up when he learned about a new forecasting model from the U.S. Geological Survey and the National Oceanic and Atmospheric Association that’s intended to give a better idea of how much ocean water will overrun an area.
“Any and all information is always helpful,” says Couch, who owns the Lighthouse Service Center and Lighthouse Auto Parts along North Carolina’s Outer Banks. “You don’t want to put up stuff unless you really have to.”
The USGS is running its coastal change forecast model to predict how far a storm’s waves will push water up the beach — whether it will go just to the dunes, over the dunes, or even farther onto roads and property. Oceanographers are in the pilot stages of a new implementation of the model that would predict beach changes in all weather conditions.
As part of the pilot program, hour-by-hour forecasts of potential beachfront changes caused by wave conditions are underway in some areas of North Carolina, Massachusetts and Florida, said USGS research oceanographer Hilary Stockdon. The pilot program runs all the time for all sorts of weather, not just big storms such as hurricanes and nor’easters. Eventually, the forecasts — which give details for the coming days — will be available for all Gulf and Atlantic states up to 102 hours before storms.
The pilot program was running in North Carolina during recent Tropical Storms Bonnie and Colin, but the forecasts aren’t yet available publicly. Officials hope the information for the three states will be online in three months.
“In places like the Outer Banks, there could be a high tide and winds from a particular direction that are going to overwash Highway 12 and cut off transportation,” Stockdon said, referring to the narrow road that provides the only nonferry access to Hatteras Island. “Those are the kind of events we want to be able to help locals with.”
Since 2011, the model has been used to forecast coastal change during storms that make landfall. USGS used it most recently when Colin made landfall in Florida; researchers are studying the results to determine the accuracy of their forecasts. Those are available to the public through the USGS coastal change hazards portal.
The model adds data about what’s called wave run-up to information on storm surge and tides. That results in a total on the amount of water that will come ashore in any kind of storm, said USGS research oceanographer Joseph Long. Storm surge measures how high the ocean will rise; wave run-up determines how big the waves will be at the shoreline, on top of the rising ocean.