Influence of Atmospheric Rivers on Long-Duration Freezing Rain Events in Eastern North America

Notable damaging freezing rain events (e.g., 5-9 January 1998 and 21-23 December 2013) in eastern North America have been connected to mid-latitude synoptic-scale storms having strong poleward transport of sub-tropical moisture in narrow-banded lower-tropospheric warm sector features known as atmospheric rivers (ARs). The purpose of this study is to document the frequency that long-duration freezing rain events of two study domains in eastern North America were linked to ARs over a 37-year period, 1 January 1979 – 31 December 2015. Generally, the duration of a freezing rain event is related to its severity. Hence, the study will examine the hypothesis that severe freezing rain events of eastern North America are likely to have an AR influence.

The long-duration freezing rain events database of McCray et al. (2019) is compared to the Climate Forecast System Reanalysis-based ARs database of Guan and Waliser (2015) for the northeastern United States/southeastern Canada (NEUS/SECA) and southeastern United States (SEUS) study domains defined by McCray to examine the contribution of atmospheric rivers to these particularly destructive cool season events. Of particular interest will be to examine and contrast synoptic-scale composite patterns of AR-influenced freezing rain events impacting the NEUS-SECA domain to those impacting the SEUS domain.