A new report from nonprofit science and technology group First Street Foundation, in partnership with global sustainable development consultancy Arup, provides a peer-reviewed wind model that uses open science to identify the likelihood and financial impacts of tropical cyclones for all properties in the contiguous United States today, and up to 30 years in the future under a changing climate. Titled “The 7th National Risk Assessment: Worsening Winds,” the report combines high resolution measurements of well over 50,000 synthetic storm tracks to determine likely sustained wind direction and speed, adjust for local surface roughness effects on wind speed, and quantify the probability and magnitude of 3-second gusts that drive the majority of wind-related losses.
The model finds that over the next 30 years, over 13.4 million properties that are not currently at risk will be exposed to tropical cyclones. This increasing exposure is due the greater proportion of hurricanes that are expected to reach major hurricane status (Category 3-5 on the Saffir-Simpson Scale) today and into the future, and the greater likelihood that storms will track further northward along the US East Coast. The research also demonstrates that Florida, the most exposed state, can expect a shift in the landfall of hurricanes from the south in cities such as Miami, to more northern locations, such as Jacksonville. This shift in location and strength of hurricanes in Florida alone results in a dramatic increase in the number of properties that may face a Category 5 hurricane, rising from 2.5 million in 2023 to an anticipated 4.1 million by 2053.
Building on the methodology for past reports, including “The 5th National Risk Assessment: Fueling the Flames” and “The 4th National Risk Assessment: Climbing Commercial Closures,” Arup provided data-driven vulnerability and consequence models that help calculate the dollar value of expected damage and the associated downtime for each specific building structure, accounting for factors like the number of stories, whether the property is residential or commercial , the spatial orientation of the building, roof type, building materials, and more. These property level damage estimates show that, on average, the country can expect to see an annual loss of $18.5bn this year resulting from hurricane winds, increasing to just under $20bn in 30 years. Of that $1.5bn in increased damages, the vast majority of that, roughly $1bn, comes from increased exposure in Florida alone.