Investigating the Occurrence of Blizzard Events over the Contiguous United States Using Observations and Climate Projections

Over previous decades, the United States has been plagued by severe winter storms or blizzards, which caused millions of dollars in damages. However, the historical trend of blizzard events and the possible impacts of global climate change on blizzard occurrences remain unclear. In this study, we analyzed historical blizzard occurrences using the observed storm events database, which shows that the Northern Plains, such as North Dakota, South Dakota, and Minnesota, had the most blizzard activities over the past 25 years. No significant trend in blizzard occurrence is found in those regions. When considering blizzards as compound events of strong wind and extreme snowfall, we estimated blizzard occurrences based on wind speed and snowfall in gridded climate datasets, including EAR5 reanalysis and historical simulations of 19 models in Coupled Model Intercomparison Project phase 6 (CMIP6), which both show a good agreement with the observations. By the end of the century, CMIP6 projections suggest decreases in both strong wind and extreme snowfall events, eventually leading to a significantly reduced frequency of compound events. Significant decreases in blizzard occurrence are found in the Northern Rockies and Plains, and Upper Midwest, suggesting potentially reducing the risk of winter hazards over those regions in a warming climate.