Relationships Between Great Lakes Extratropical Cyclone Characteristics and Global Teleconnections

Abstract The Great Lakes Region sits at the intersection of multiple North American storm tracks. During the cold season (October–March), the regional weather is dominated by extratropical cyclone activity. While these Great Lakes extratropical cyclones (GL ETCs) are getting warmer and holding more moisture with time, there is considerable interannual variability in storm characteristics. To better understand cold‐season variability, this study investigates the correlations between GL ETC thermodynamic characteristics and different global teleconnection patterns. Using a database of 886 cyclones identified in ERA5 data, we find that while there is no correlation between teleconnection indices and the number of GL ETCs each year, the Pacific North American and North Pacific Gyre Oscillation (NPGO) indices are significantly correlated with the moisture content in GL ETCs, and the North American Oscillation is correlated with ETC temperature. The Arctic Oscillation is correlated with all thermodynamic characteristics in GL ETCs. Additionally, the relationships between GL ETCs and teleconnection indices are shifting with time, and some teleconnections, like the NPGO, may become more influential to Great Lakes weather in the future.