Likelihood of back-to-back tropical cyclone hazards is increasing
Study key findings & significance
- Models show that even a moderate-emissions scenario increases the chances of back-to-back tropical cyclone hazards and, possibly, two extreme tropical cyclone events impacting the United States within a short period of time.
- The researchers said their study showed that sequential storms have become more common on the East Coast and the Gulf Coast, although they remain relatively rare.
"Rising sea levels and climate change make sequential damaging hurricanes more likely as the century progresses. Today's extremely rare events will become far more frequent."
Dazhi Xi, lead author
"Sequential hurricane hazards are happening already, so we felt they should be studied. There has been an increasing trend in recent decades."
Ning Lin, an associate professor civil and environmental engineering at Princeton University
Two tropical cyclones (TCs) that make landfall close together can induce sequential hazards to coastal areas. Here we investigate the change in sequential TC hazards in the historical and future projected climates. We find that the chance of sequential TC hazards has been increasing over the past several decades at many US locations. Under the high (moderate) emission scenario, the chance of hazards from two TCs impacting the same location within 15 days may substantially increase, with the return period decreasing over the century from 10–92 years to ~1–2 (1–3) years along the US East and Gulf coasts, due to sea-level rise and storm climatology change. Climate change can also cause unprecedented compounding of extreme hazards at the regional level. A Katrina-like TC and a Harvey-like TC impacting the United States within 15 days of each other, which is non-existent in the control simulation for over 1,000 years, is projected to have an annual occurrence probability of more than 1% by the end of the century under the high emission scenario.