LSU Partnerships Improve Hurricane Storm Surge Forecasts for Louisiana, Nation

BATON ROUGE – During the record-breaking 2020 hurricane season, more people than ever turned to LSU’s Coastal Emergency Risk Assessment, or CERA tool, which visualizes ADCIRC storm surge predictions, to help protect people and assets against flooding. Although the official season finally ended last week, the researchers are busier than ever in improving the tool and preparing for next year—by working directly with the decision makers who rely on it.
“Nothing represents reality like reality,” said Windell Curole, general manager of the South Lafourche Levee District, as he watched the fifth named storm of the already record-breaking 2020 hurricane season make landfall in Louisiana with Hurricane Zeta last Oct. 28. “As an emergency manager, you look for every piece of information at your disposal. And when you make your call—more than a day ahead of landfall—and you’re telling people to evacuate or open or close flood gates, you’d better be right.”
He understands the risks involved with basing decisions on guesstimates or telling people the wrong thing—they won’t evacuate when they should; whether it’s this time, if you don’t tell them to, or next time, if you tell them to evacuate and it turns out they didn’t need to.
“You can evacuate to naturally high ground to get away from the surge, but if you are not out in time, you can’t leave,” Curole said. “Greater danger and loss of life comes with storm surge not wind.”
He and thousands of other emergency managers along the Gulf Coast and Atlantic Seaboard have come to rely on the CERA visualization tool developed at LSU to help make some of their most difficult decisions in guarding local populations against storm surge. CERA, which relies on storm surge predictions computed by the ADCIRC surge guidance system, or ASGS, developed in collaboration with the University of North Carolina, provides a quick visual interpretation of millions of computer data points to show flooding risks during a storm.
As Hurricane Eta zigzagged into the Gulf of Mexico about a week after Zeta and there was uncertainty about the storm’s track after it first devastated parts of Central America and then inundated Cuba and southern Florida, Curole sent LSU a straight-forward yet complicated question: What if Eta, instead of heading back across Florida as predicted, would come straight up across the Gulf of Mexico and hit Lafourche Parish? Then what?
Curole’s question reached Carola Kaiser, CERA lead developer and IT Consultant at LSU’s Center for Computation & Technology, or CCT, which houses seven servers that power CERA. She was fielding a record 243 new user login requests from across the nation, including the U.S. Coast Guard, the U.S. Army Corps of Engineers, FEMA, NASA, the U.S. Navy, the Department of Defense, the Department of Homeland Security, the Department of Transportation, the Department of Health & Human Services, several oil and gas companies, local and national law enforcement, media outlets such as The Washington Post and ProPublica, and around Louisiana—levee districts, the National Guard, the Coastal Protection and Restoration Authority, or CPRA, and the Governor’s Office of Homeland Security and Emergency Preparedness, or GOHSEP. She’d already established a White House Situation Room login.
What-if scenarios are an integral part of CERA for decision makers who can access layered maps in such high resolution they potentially show differences between neighboring houses. That information is not available to the general public at cera.coastalrisk.live, as that amount of detail easily could convey a false sense of certainty about what’s going to happen and what individual residents should do, which might contradict general area evacuation orders. Plus, predictions change. Every six hours, as the National Hurricane Center, or NHC, issues its forecast advisories, ASGS recomputes all available flood level data, allowing CERA to update its maps within an hour or two, in time for critical briefings at every level.
A key recipient of this information in Louisiana is the CPRA. Since 2018, the CPRA has provided annual funding to LSU to support the overall forecasting efforts of CERA and ASGS. Their primary concern is the management of the intricate system of tide and flood gates throughout the state, as well as overseeing the complicated system of levees.
“The CERA tool is very important to CPRA—not only for operation of hurricane risk-reduction systems, but also for the prepositioning of flood-fighting assets,” said CPRA Operations Chief Ignacio Harrouch. “Keeping the model as up-to-date as possible is key, and this is why CPRA continuously collects and shares bathymetric and topographic data with LSU to facilitate continued improvement of the model.”
This year, the LSU CERA website broke its seasonal record in visits for Hurricanes Laura and Marco, with 10,223 unique users.
“For the general public, we need to make the information as easy-to-understand and clear as possible, so we don’t give out any misguidance,” Kaiser said.
To read this full story including the history of CERA and LSU’s storm surge forecasting expertise, visit: https://www.lsu.edu/research/news/2020/1202-stormsurgeforecasting.php.