An Expanded Investigation of Atmospheric Rivers in the Southern Appalachian Mountains and Their Connection to Landslides

Abstract

Previous examination of rain gauge observations over a five-year period at high elevations within a river basin of the southern Appalachian Mountains showed that half of the extreme (upper 2.5%) rainfall events were associated with an atmospheric river (AR). Of these extreme events having an AR association, over 73% were linked to a societal hazard at downstream locations in eastern Tennessee and western North Carolina. Our analysis in this study was expanded to investigate AR effects in the southern Appalachian Mountains on two river basins, located 60 km apart, and examine their influence on extreme rainfall, periods of elevated precipitation and landslide events over two time periods, the ‘recent’ and ‘distant’ past. Results showed that slightly more than half of the extreme rainfall events were directly attributable to an AR in both river basins. However, there was disagreement on individual ARs influencing extreme rainfall events in each basin, seemingly a reflection of its proximity to the Blue Ridge Escarpment and the localized terrain lining the river basin boundary. Days having at least one landslide occurring in western North Carolina were found to be correlated with long periods of elevated precipitation, which often also corresponded to the influence of ARs and extreme rainfall events.

Non‐linear quickflow response as indicators of runoff generation mechanisms

“…Similarly, the relief at SHW is only 54 m and imparts no orographic effect. Rainstorms vary throughout the year in both study locations and tend to be more convective in the summer and more frontal in the winter (Laseter, Ford, Vose, & Swift, 2012; Miller, Miniat, Wooten, & Barros, 2019). At CHL, spatial patterns of rainfall are reinforced more strongly by elevation during the summer months (Daly, Slater, Roberti, Laseter, & Swift, 2017), likely due to convective storms generating over higher elevations.…”

The Influence of Atmospheric Rivers on Cold‐Season Precipitation in the Upper Great Lakes Region

“…Inland ARs have been linked to heavier precipitation and flooding in the central U.S. (Lavers & Villarini, 2013; Nayak et al., 2016) and landslides in the Appalachian Mountains (Miller et al. 2019). In this work, we extend these previous analyses of inland AR impacts to the Upper Great Lakes region, located in the northern mid‐latitudes.…”

On the emerging global relevance of atmospheric rivers and impacts on landscapes and water resources

“…Similarly, a 22-yr study in California showed that 60–90% of shallow landslides coincide with atmospheric rivers (Oakley et al, 2018). Landslides are also important hazards in other mountainous areas; thus, the AR-landslide relationship has begun to be investigated in other regions, including the Southeast U.S. (Miller et al, 2019).…”