The Influence of Sea Surface Temperature Gradients on the Rapid Weakening of Tropical Cyclones

As the coastal population has increased in the United States, a greater number of people are now at risk of impacts from tropical cyclones (TCs) that either make landfall or come close to making landfall. Rapid changes in intensity can strongly affect a coastal region’s preparations for a TC, yet predicting these intensity changes remains a challenge, especially for rapidly intensifying (+30 kt in 24 h) or over-water rapidly weakening (-30 kt in 24 h) storms. Previous research has explored the physical processes that might lead to rapid intensification; however, less work has been done on exploring the contributing factors that might lead to the over-water rapid weakening of a TC.

This poster presentation will investigate how rapid weakening is affected by sea surface temperature (SST) gradient magnitude and direction relative to the motion of a TC. We suspect the likelihood of rapid weakening increases as a TC moves parallel to a strong, negative SST gradient. Additionally, we will use infrared satellite data to determine structural changes in convection prior to a TC undergoing rapid weakening as it approaches strong SST gradients. While this study will focus on rapid weakening cases in the eastern north Pacific, these findings may be applicable to TCs interacting with SST gradients in other basins.