Atmospheric Rivers and Their Relationship to Snowfall in the Northeastern United States

Atmospheric rivers (ARs) have been frequently studied along the west coast of the United States. Rutz et al. (2014) defines an AR as having values of integrated water vapor transport (IVT) of at least 250 kg/m/s over a length of at least 2,000 km and often less than 1000-km wide. The purpose of this study is to create a 30-year climatology of ARs in the northeastern U.S. and utilize this climatology to examine their relationship to snowfall at cities across the northeast. In general, ARs tended to occur on at least 15–20% of all snowfall days greater than a trace across all northeastern U. S. cities. This value rose to nearly 40% for cities along the immediate coast of the Atlantic Ocean. This increase toward the coast mirrored the spatial distribution of ARs in the 30-year climatology, which also maximized along the coastal regions of the northeast. The percent of snowfall days associated with ARs was relatively consistent for all snowfall thresholds, indicating that larger snowfall amounts aren’t necessarily associated with a greater frequency of ARs.