DHS Storm Surge Tool Helps Emergency Managers Prepare
In June, as Tropical Storm Cindy approached the Texas and Louisiana coastlines, Texas authorities who operate the ferries along the state’s Gulf Coast were using a combination of online tools and observations to monitor water heights. A rise of 4½ feet in water levels meant the ferries—a key component of the state’s hurricane evacuation plan—couldn’t operate. If that happened, the Texas National Guard wouldn’t be able to use them to help evacuate the Bolivar Peninsula. Instead they’d have to drive two hours around the peninsula to reposition themselves.
That appeared to be the unhappy forecast as the storm approached. But at the same time, ADCIRC—a tool funded by the Department of Homeland Security’s Science and Technology Directorate to model storm surge and coastal flooding—was forecasting less rise along the Texas coast. Based on that data, Dr. Gordon Wells, of the University of Texas’ Center for Space Research, who’d been monitoring the ADCIRC info via the Coastal Emergency Risks Assessment website, concluded the water height wouldn’t top four feet. As a result, Texas didn’t shut down its ferries, and a crucial emergency transportation link for citizens and responders remained intact.
NOAA tide gauges later showed the ADCIRC predictions came within 0.2–0.3 feet of the actual recorded measurements.
ADCIRC, combined with meteorological forecasts like rain, atmospheric pressure and wind forecasts, predicts flooding threats, allowing emergency managers and other decision makers to make better decisions about response efforts before severe weather occurs.
Used by a variety of federal, state, regional and local organizations, including National Weather Service offices, the U.S. Army Corps of Engineers, FEMA and the U.S. Coast Guard, ADCIRC has evolved since 2008 as a highly valuable forecasting tool for pre-storm operations.
The system was used during Hurricanes Irene, Isaac, Sandy, Matthew and most recently, Hurricanes Harvey and Irma.
“The model was key to my decision regarding aircraft protection in Puerto Rico, and our decision to relocate our command center out of Miami. I’ll be watching it with every update,” says Coast Guard Rear Admiral Peter Brown, Commander of District 7, which includes most of Florida, Georgia and South Carolina. He used ADCIRC results to plan for evacuation of USCG staff during Hurricane Irma.
Dr. Rick Luettich, who leads the Coastal Resilience Center, says recent funding has improved ADCIRC, increasing connectivity to emergency operators and the development of platforms such as the Coastal Emergency Risks Assessment website that make model results accessible to users. The site is free for anyone to use.
“We now have an established ADCIRC university research and supercomputing network that activates ahead of every storm to provide information for planning and operations,” says Luettich. “We strive to get the best possible information out to the people who need it when they need it—and that means having researchers who are working side-by-side with emergency managers ahead of a storm.”
The network includes research centers in Texas, Louisiana, Indiana, North Carolina and Florida, all of which work closely with their state emergency management departments.
“The Coastal Resilience Center and its ADCIRC team have become a key resource for our operational partners such as the U.S. Coast Guard, who have to make tough calls as hurricanes approach the United States,” says Dr. Matthew Clark, director of the DHS S&T Office of University Programs.