North Atlantic Hurricane Winds in Warmer Seas

Tropical cyclones devastate coastlines around the world. The United States and surrounding areas experienced multiple extreme events in the 2017 hurricane season. Understanding extreme hurricanes and how they may change in a warming environment is an important area of climate research. This study makes use of the significant, positive relationship between the average August–October sea surface temperatures and the per-event observed maximum hurricane wind speeds across the North Atlantic Basin using data from 1851–2016. The slope of the best-fit line is applied to the observed maximum wind speeds across the basin to increase the wind speeds to a one, two, and three-degree warmer sea surface. These increased winds are referred to as one, two, or three-degree warmer winds. These warmer winds are put into a generalized Pareto peaks-over threshold model to estimate the return levels for various return periods across a hexagonal tessellation of the North Atlantic. Viewing the results spatially allows for geographic patterns to emerge. Comparisons between the extreme value modeled distributions using the observed wind speeds and the warmer winds’ distributions are shown to be significantly different. This study provides return estimates for extreme hurricane winds in a world with warmer sea surfaces in the hopes to better inform those making important, life-saving decisions along the U.S. and neighboring coasts.