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

Abstract

AbstractThis study aims to identify the impacts of atmospheric rivers (AR) associated with cold‐season precipitation in the Upper Great Lakes region of the United States. A MERRA‐2‐derived AR dataset is combined with data from a suite of instruments hosted by the National Weather Service in Marquette, Michigan, including a profiling radar and a video disdrometer. ARs coincide with deep, synoptically‐forced precipitation 28% of the time during the cold season. These ARs are found to intrude from the southwest and are associated with warmer surface and upper‐level temperatures, increased radar reflectivity values, and enhanced precipitation rates. Warmer atmospheric temperatures aloft associated with ARs lead to a fourfold increase in the likelihood that cold‐season precipitation will be rain instead of snow. Additionally, inland ARs in the Upper Great Lakes region are correlated with the negative phases of the Pacific Decadal Oscillation and the Pacific‐North American pattern.