The Future of Snowstorms in Central and Eastern North America

We investigate the changing snowstorm landscape in eastern North America using dynamically downscaled regional climate simulations that compare the late-20th century against mid- and late-21st-century epochs for two climate pathways that include moderate and pessimistic warming. By identifying, tracking, and cataloguing snowstorms, we illustrate how the frequency, snow water equivalent, and other features of these events may change. Results suggest changes in snowstorm characteristics are most significant for the pessimistic pathway, especially toward the late 21st century. There is similar event frequency between the historical period and mid-21st-century projections but declines of 3% to 10% are still projected for snowstorm counts, hours, cumulative area, and snow water equivalent. By the late 21st century, snowstorm attributes have losses of 6% to 37% versus the historical period, revealing a projected acceleration in loss from the mid to late century. Spatially, snowstorm reduction is most dramatic along and south of the Ohio River Valley as the latitude that separates steady snowstorm counts to the north and reduced snowstorms to the south migrates poleward in the future. Similarly, extreme snowstorms decline to the south, with some northern regions experiencing increase in counts and snow water equivalent, affirming prior research theorising that some snowfall may intensify as increasing moisture in a warming climate interacts with environments with temperatures still supportive of snowfall. Significant reductions in early and late cool-season snowstorms are projected across all future epochs, revealing a shrinking season. These results provide a set of perspectives on how a dominant cryospheric input-the snowstorm-will change across eastern North America in the future.