Abstract
Atmospheric rivers (ARs) effect inland hydrological impacts related to
extreme precipitation. However, little is known about the possible
coastal hazards associated with these events. Here we elucidate
high-tide floods (HTFs) and storm surges during ARs on the US West Coast
during 1980—2016. HTFs and landfalling ARs co-occur more often than
expected from random chance. Between 10%—63% of HTFs coincide with
landfalling ARs, depending on location. However, only 2%—15% of ARs
coincide with HTFs, suggesting that ARs typically must co-occur with
anomalously high tides or mean sea levels to cause HTFs. Storm surges
during ARs are interpretable in terms of local wind, pressure, and
precipitation forcing: meridional wind and barometric pressure are the
primary drivers of storm surge, but precipitation can also make
secondary contributions. This study highlights the relevance of ARs to
coastal impacts, clarifies the drivers of storm surge during ARs, and
identifies future research directions.