(Bloomberg) -- Hurricanes bring to mind wind-bent palm trees, whipped up surf and damaged coastal cities. But as Hurricane Ian gains strength and curves back to the mainland for the third act of its devastating performance in Florida and Cuba, the storm is set to demonstrate the long, inland tail of storms made stronger by climate change.
Rains and flooding impacts from hurricanes are felt far away from the shore. “These storms very often carry with them incredible amounts of rainfall,” said Kate Abshire, who studies flash floods for the National Weather Service, “and bring that rain very far inland.”
Flooding like this not only causes much more death than winds or storm surges—it also causes a great deal of property damage in areas that are historically underinsured.
“Low-income communities haven’t had the resources to take mitigation measures,” said Samantha Montano, an assistant professor of emergency management at Massachusetts Maritime Academy. “The state of infrastructure is weak, building codes don’t anticipate flooding.”
A warming world delivers more fuel for hurricanes, which draw energy from hotter, tropical waters and hotter air that holds more moisture. So these storms are not only becoming more intense, they’re also inching poleward more and more every decade. In the southern Appalachian Mountains, a long way from the ocean, flooding traditionally peaked across the in late winter to early spring as snow melted. But now an increase in a second wave of annual deluges occurs between August and October, which is likely due to the remnants of tropical systems, according to a report by the National Weather Service.The impacts don’t end there. Last year’s Hurricane Ida, which hit Louisiana as a Category 4, sustained itself for days until it dumped torrential rains on New York and New Jersey, killing more than a score of people and costing billions as it flooded highways, transit systems and basements. Five days after shorting out Puerto Rico's power grid as a hurricane, a slowed yet still powerful Fiona brought as much as $1.5 billion in damage to eastern Nova Scotia, the strongest storm ever to hit the area.
Ian looks set to follow in those footsteps. South Carolina could receive as much 8 inches, mainly on Friday, the National Hurricane Center said. Some areas could get as much as 12 inches. Flooding rains will also fall across North Carolina, Georgia and Virginia. The governors of all four states joined Florida in declaring emergencies.
It's possible that more than 5 inches of rain could fall as far north as coastal New Jersey, and up to 2 inches in Pennsylvania, across Long Island and even on Cape Cod in Massachusetts.Extreme weather is a peril for U.S. infrastructure not designed—or insured— to endure such conditions. Many homes in the Appalachia region that includes Pennsylvania have inadequate flood protection and a longstanding practice of underestimating storms. In the U.S., 95% of residential flood insurance is underwritten by a branch of the Federal Emergency Management Agency. The agency also makes the maps that designate broad flood risk zones and help determine the need for such insurance. If a home is in one of the severe risk areas, homeowners with a federally backed mortgage must buy insurance from the National Flood Insurance Program.
But FEMA administrator Deanne Criswell recently said that the agency’s maps are out of date because climate change is intensifying storm events. How wrong are the maps?
First Street Foundation, a nonprofit research institution, evaluated flood risks for every property in 48 contiguous states in 2020, using techniques pioneered by the insurance industry. That approach found 6 million additional homes that should be in the severe flood-risk zones, a huge chunk of which were in Appalachia.
“We have built and continue to build to a standard that is not high enough to withstand today’s risk, let alone the risks we know we will face in the near future,” said Matthew Eby, First Street’s chief executive officer.
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