Recent increases in tropical cyclone precipitation extremes over the US east coast

The impacts of inland flooding caused by tropical cyclones (TCs), including loss of life, infrastructure disruption, and alteration of natural landscapes, have increased over recent decades. While these impacts are well documented, changes in TC precipitation extremes- the proximate cause of such inland flooding-have been more difficult to detect. Here, we present a latewood tree-ring-based record of seasonal (June 1 through October 15) TC precipitation sums (sigma TCP) from the region in North America that receives the most sigma TCP: coastal North and South Carolina. Our 319-y-long sigma TCP reconstruction reveals that sigma TCP extremes (>0.95 quantile) have increased by 2 to 4 mm/decade since 1700 CE, with most of the increase occurring in the last 60 y. Consistent with the hypothesis that TCs are moving slower under anthropogenic climate change, we show that seasonal sigma TCP along the US East Coast are positively related to seasonal average TC duration and TC translation speed.

Automated summary

The study found that tropical cyclone precipitation extremes have increased in North America's coastal regions over the past few centuries, especially in the last 60 years, indicating a consistent trend with slower movement speeds of tropical cyclones under anthropogenic climate change.