According to new model projections, Louisiana and Florida could be twice as likely by the end of the century to experience two tropical storms that make landfall within nine days of each other. When two storms hit in quick succession, communities and infrastructure have less time to recover between disasters.
The time between tropical storms making landfall on the Gulf Coast has been decreasing over the last four decades. According to new model projections, Louisiana and Florida could be twice as likely by the end of the century to experience two tropical storms that make landfall within nine days of each other.
More tropical storms have been packed into a single hurricane season as global climate changes, which typically runs from June to November in the Gulf region. According to new findings published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences, the time between storms in the region is shrinking.
In previous research, people have mostly focused on the resilience of infrastructure, rather than the time to restore it after a storm. If it takes 15 days to restore infrastructure, such as a power system, after a storm, and the second storm hits before the system can recover, residents will face dangerous conditions.
Dazhi Xi
Florida and Louisiana are the most likely to see “sequential landfall,” which occurs when a hurricane moves over land faster than infrastructure damaged by a previous storm can be repaired. The researchers estimate that the time between hurricanes in those states is 10 days. Being hit by two storms in quick succession gives communities and infrastructure less time to recover between disasters — a significant problem for a region with a swelling population that has struggled to recover following previous natural disasters.
“In previous research, people have mostly focused on the resilience of infrastructure, rather than the time to restore it after a storm,” said Dazhi Xi, the study’s lead author and a climate scientist at Princeton University.
The stresses on infrastructure, ecosystems, and people are heightened as the storm season lengthens and the time between disasters shortens.
“If it takes 15 days to restore infrastructure, such as a power system, after a storm, and the second storm hits before the system can recover, residents will face dangerous conditions,” Xi said. Sequential tropical storms exacerbate problems with health risks, rescue, and clean-up operations, and restoring systems in a community without power, transportation, or communications.
More cyclones, more problems
The study looked at hurricane seasons from 1979 to 2020, focusing on years when at least two tropical storms made landfall in the same region within two weeks of each other. Xi examined how that number changed over time and combined it with a climate model to estimate how the number of back-to-back hurricanes would change over time. Xi also divided the Gulf Coast into regions to determine which areas are most vulnerable to these sequential storms in the past and in the future. He discovered that Louisiana and Florida are the most likely places for multiple tropical storms to strike, but the entire coast will see more storms.
The number of tropical storms is projected to grow rapidly even relative to the lengthening hurricane season, Xi said.
The need to prioritize faster disaster recovery times was highlighted earlier this year by an extreme cold snap in Texas in February, which knocked out much of the state’s power grid. That disaster was followed by Tropical Storm Henri, which flooded New York’s subway system in August, and Hurricane Ida, which hit Louisiana in September – a state that was still “reeling” from last year’s hurricane season, with three consecutive landfalling storms, according to hurricane climatologist and geographer Jill Trepanier of Louisiana State University, who was not involved in the study.
“Even the best-case scenario of this worst-case scenario spells disaster for the coast,” Trepanier said. “That is why there are climate refugees. They are people who have been displaced because they can no longer live in a certain area due to changing weather patterns. We can’t have people living there if we can’t restore power grid structures, adequately house people, or provide water and other resources.”
