As this year's hurricane season approaches, many are wondering if the 10-year drought of major hurricane landfalls experienced by the U.S. will come to an end. Many factors influence hurricane dynamics, but one of the most important is sea surface temperature (SST). Warm water—SSTs of at least 26°C (78.8°F) to a depth of 50 m (164 feet) below the ocean surface—is one of the elements essential for tropical cyclone formation. Elevated SSTs, such as those experienced in recent years, provide even more heat energy to fuel storm development.
Since the high-loss and very active hurricane seasons of 2004 and 2005—which occurred 10 years into a sustained period of elevated Atlantic SSTs—catastrophe modelers have been using various techniques to help users better assess the sensitivity of Atlantic hurricane risk to a warm ocean climate.
A 2015 AIR issue brief examined the relative effectiveness of those different approaches. Broad readership prompted a follow-up survey to better understand the impact of elevated SSTs on hurricane modeling workflows.
Survey Signals High Use of Alternative Catalog
Our survey revealed that the warm Atlantic Ocean climate most definitely has impacted hurricane risk modeling. Of the survey respondents, 78% indicated that elevated SSTs have affected their approach to hurricane modeling since the 2004–2005 seasons.
We also learned that model users share a strong interest in accessing alternative views of risk. With regard to catalogs offered by AIR, 53% of the respondents use both the standard catalog and the WSST catalog, 30% use only the WSST catalog, and 17% use only the standard catalog.
Two-thirds of respondents feel their modeling tools "adequately address" elevated SSTs. When asked if AIR should offer other climate-conditioned catalogs, about one-third of survey respondents showed interest an El Niño Southern Oscillation catalog, and one-quarter expressed interest in a cool-SST view. Only 18% were interested in a North Atlantic Oscillation catalog, with only about 10% suggesting Madden Julian Oscillation and Quasi Biennial Oscillation catalogs.
For additional information, see "A Retrospective on 10 Years of Modeling Hurricane Risk in a Warm Ocean Climate."