The average speed of tropical cyclone (TC) translation has slowed since the mid 20th century. Here we report that North Atlantic (NA) TCs have become increasingly likely to “stall” near the coast, spending many hours in confined regions. The stalling is driven not only by slower translation, but also by an increase in abrupt changes of direction. We compute residence-time distributions for TCs in confined coastal regions, and find that the tails of these distributions have increased significantly. We also show that TCs stalling over a region result in more rain on the region. Together, increased stalling and increased rain during stalls imply increased coastal rainfall from TCs, other factors equal. Although the data are sparse, we do in fact find a significant positive trend in coastal annual-mean rainfall 1948–2017 from TCs that stall, and we verify that this is due to increased stalling frequency. We make no attribution to anthropogenic climate forcing for the stalling or rainfall; the trends could be due to low frequency natural variability. Regardless of the cause, the significant increases in TC stalling frequency and high potential for associated increases in rainfall have very likely exacerbated TC hazards for coastal populations.

自20世纪中叶以来，热带气旋（TC）的平均翻译速度有所下降。在这里，我们报告说，北大西洋（NA）TC越来越有可能“停滞”在海岸附近，并在密闭地区花费了许多小时。失速不仅由较慢的平移驱动，还由方向突然变化的增加驱动。我们计算了密闭沿海地区TC的停留时间分布，发现这些分布的尾部显着增加。我们还表明，某个地区的TC拖延会导致该地区更多的降雨。总的来说，失速增加和失速期间降雨增加意味着来自TC的沿海降雨增加，其他因素相同。尽管数据稀少，但实际上，我们确实发现，由于停滞不前的TC，沿海地区1948-2017年的年平均降雨量呈明显的正趋势，并且我们确认这是由于停顿频率增加所致。我们没有将人为的气候强迫归因于停滞或降雨。趋势可能是由于低频自然变异。无论原因如何，TC停顿频率的显着增加以及随之而来的降雨增加的潜在可能性很可能加剧了沿海人口的TC危害。