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Abstract Hurricane Hilary brought extensive, record‐breaking precipitation to the Southwest United States in August 2023. Although tropical cyclones (TCs) are uncommon in this region, they can cause substantial damage, primarily through flooding. However, heat extremes associated with these TCs are understudied and could have significant impacts in populated coastal areas. This study examines the conditions that promoted the occurrence of 42 north‐reaching, northeastern Pacific TCs and quantifies how local temperatures responded to these storms. Using composite analysis, we find that there is significant warming along the coastal region of Southern California preceding a TC, particularly for storms that remain offshore. Three main mechanisms contribute to this warming pattern—adiabatic compression associated with downslope winds, warm air advection by the TC itself, and suppression of coastal upwelling. These compound heatwave‐TC events are an overlooked impact of TCs that will likely become more important as the climate warms.
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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 (ΣTCP) from the region in North America that receives the most ΣTCP: coastal North and South Carolina. Our 319-y-long ΣTCP reconstruction reveals that ΣTCP 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 ΣTCP along the US East Coast are positively related to seasonal average TC duration and TC translation speed.
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- Award ID(s):
- 2102888
- PAR ID:
- 10307949
- Publisher / Repository:
- Proceedings of the National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 118
- Issue:
- 41
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- Article No. e2105636118
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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